Clusters should not be sorted from Major to Supporting and then taught in that order. To do so would strip the coherence of the mathematical ideas and miss the opportunity to enhance the major work of the grade with the supporting clusters.
Clusters should not be sorted from Major to Supporting and then taught in that order. To do so would strip the coherence of the mathematical ideas and miss the opportunity to enhance the major work of the grade with the supporting clusters.
Code  Description  
MAFS.4.NBT.2.4:  Fluently add and subtract multidigit whole numbers using the
standard algorithm.
 
MAFS.4.NBT.2.5:  Multiply a whole number of up to four digits by a onedigit whole
number, and multiply two twodigit numbers, using strategies based
on place value and the properties of operations. Illustrate and explain
the calculation by using equations, rectangular arrays, and/or area
models.
 
MAFS.4.NBT.2.6:  Find wholenumber quotients and remainders with up to fourdigit
dividends and onedigit divisors, using strategies based on place
value, the properties of operations, and/or the relationship between
multiplication and division. Illustrate and explain the calculation by
using equations, rectangular arrays, and/or area models.

Access Point Number  Access Point Title 
MAFS.4.NBT.2.AP.5a:  Solve a twodigit by onedigit whole number multiplication problem using two different strategies. 
MAFS.4.NBT.2.AP.4a:  Solve multidigit addition and subtraction problems within 1,000. 
MAFS.4.NBT.2.AP.6a:  Find wholenumber quotients and remainders with up to threedigit dividends and onedigit divisors, using two different strategies. 
Name  Description 
CPALMS Aquarium: Part 3 Division with Larger Numbers:  Learn more about division with larger numbers in this aquariumthemed, interactive tutorial. This is part 3 of in a threepart series. Click below to learn different strategies to help you become more efficient with division. 
CPALMS Aquarium Part 2: Division Strategies:  Learn to solve division challenges using the partial quotients strategy with this interactive tutorial. This is the second tutorial is a series on division strategies. 
CPALMS Aquarium: Connecting Multiplication and Division: Part 1:  Learn how multiplication connects to division to help understand what division is in this aquariumthemed, interactive tutorial. This is part 1 of a twopart series. Click to open Part 2, Division Strategies. 
MultiDigit Multiplication Magic Part 3: Recording Partial Products:  Calculate the product of multidigit factors by decomposing factors and recording partial products in this interactive tutorial. This is part 3 in a 3part series. Click below to open the other tutorials in the series.

MultiDigit Multiplication Area Models: Part 2:  See the magical power of area models when multiplying multidigit numbers in this interactive tutorial. This is part 2 in a 3part series. Click below to open the other tutorials in the series.

MultiDigit Multiplication Magic Part 1: Arrays:  Learn to use arrays to solve multidigit multiplication problems in this interactive tutorial. This is part 1 in a 3part series. Click below to open the other tutorials in the series. 
Adding It All Up with a Standard Algorithm:  Learn to add multidigit numbers using a standard algorithm in this interactive tutorial. 
Name  Description 
Estimator Four:  In this activity, students play a game of connect four, but to place a piece on the board they have to correctly estimate an addition, multiplication, or percentage problem. Students can adjust the difficulty of the problems as well as how close the estimate has to be to the actual result. This activity allows students to practice estimating addition, multiplication, and percentages of large numbers (100s). This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Estimator Quiz:  In this activity, students are quizzed on their ability to estimate sums, products, and percentages. The student can adjust the difficulty of the problems and how close they have to be to the actual answer. This activity allows students to practice estimating addition, multiplication, or percentages of large numbers. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Arithmetic Workout:  This interactive Flash applet offers three ways for students to practice basic fact skills related to multiplication and division. Users control the challenge level by choosing the size of the blank multiplication grid displayed by the applet. In Multiply mode users type in the product that completes a multiplication sentence. In Factor mode users click a grid cell that matches a given product. In Divide mode users type in a missing factor in the displayed multiplication sentence. A sound effect and timing feature are optional. 
Who Wants to be a Mathionaire?:  This online game replicates the popular "Who Wants to be a Millionaire?" format, using multiplication facts. It's a fun way for kids to practice multiplication! 
Name  Description 
Arithmetic Quiz:  In this activity, students solve arithmetic problems involving whole numbers, integers, addition, subtraction, multiplication, and division. This activity allows students to track their progress in learning how to perform arithmetic on whole numbers and integers. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Name  Description 
The Produce Shop:  Students are asked to multiply a pair of twodigit numbers using a strategy based on place value. 
Reading Challenge:  Students are asked to multiply a fourdigit number by a onedigit number using a strategy based on place value. 
Partial Products:  Students are asked to solve two multiplication problems using a partial products strategy. 
Multiplying Using An Array or Area Model:  Students are asked to multiply a fourdigit number by a onedigit number and two, twodigit numbers using an array or area model. 
Dividing Using an Area Model:  Students are asked to interpret a division problem with a onedigit divisor that has been completed using an area model. If the student is successful, he or she is asked to complete a division problem with a onedigit divisor using an area model. 
Subtracting Using the Standard Algorithm:  Students are asked to solve two subtraction problems using the standard algorithm. 
Find the Error:  Students are asked to find the error in a partially completed subtraction problem using the standard algorithm and to solve the problem correctly. 
Addition Using the Standard Algorithm:  Students are asked to solve two addition problems using the standard algorithm. 
Book Drive:  Students are asked to solve a division problem using a strategy based on place value. 
Interpreting Division:  Students are asked to analyze and explain another student’s division work in terms of a partial quotients strategy and to apply this strategy to another division problem. 
Dividing Using Place Value:  Students are asked to complete a division problem using place value. 
Fill In The Missing Number:  Students are asked to complete subtraction problems using the standard algorithm. 
Name  Description 
The Playground Project:  Students will enjoy designing their "dream" playground while applying math and science skills in this engineering design challenge lesson. Students will find the area and perimeter of their playground designs. They will also use a budget sheet to make decisions about what to include in their playground, considering the physical properties of the materials they "purchase." 
"Life's a Breeze!":  In this Engineering Design Challenge, students must design a vessel that will carry passengers safely and quickly across a body of water by harnessing the power of the wind. Students will be given the opportunity to test and improve their vessels as they apply various math and science skills. 
Heating Up the Neighborhood:  This Engineering Design Challenge is intended to help students apply the concepts of heat insulators as they build a model house and test different materials to use as insulators, stopping the warm air from escaping and keeping the cool air out. Students will also have an opportunity to use technology in their exploration of heat energy. 
Sound Vibrations Using the Engineering Design Process:  This lesson uses the engineering design process to guide students through the exploration of sound energy and pitch. The design challenge is to produce a lowpitch tone by using different containers and liquids. Students must also create a budget to purchase supplies. 
Set Sail with STEM: Exploring Wind and Water Movement as Energy with Sailboats:  Come sail away with this STEM activity! Students will use handson inquiry to find out more about wind and its effect on sails. Through trial and error and based on data collected, students will design, build, and race their own vessel or "sailboat" across the boundless waters of a kiddie pool. Students should gain a better understanding of how moving water and air are sources of energy and can propel objects forward at varying rates of speed. 
Model Multiplication:  This concept based, handson lesson is intended to help you assess how well your students understand and can use a variety of strategies and representations of 2 twodigit multiplication. 
Modeling Multiplication for Mastery:  In this lesson, students will work to multiply multidigit numbers using various strategies. The lesson begins with a review of single x single digit numbers and progresses to twodigit x twodigit numbers. Students will use arrays, array frames with base ten blocks, and area models to explore and justify their solutions. 
Multidigit Multiplication Using Array Frames:  This is an introductory lesson and is limited to multiplication of twodigit by onedigit numbers. The students will work with base ten blocks to model their multiplication. 
Dividing for Equal Groups:  This lesson is meant to help solidify division understanding before teaching the standard algorithm. Given a situational story, students will use base 10 blocks to model division in order to solve problems. It may be used for 4th or 5th grade depending on the size of the divisor. 
I Love Leftovers!:  In this lesson, students will explore situational problems that address the different ways to interpret the remainder. 
Draw a blueprint of your dream house floor plan.:  This lesson will help your students learn about area and perimeter while imagining and drawing a blueprint of their dream house floor plan. They will have so much fun drawing and creating their blueprint they will forget that they are actually learning how to find area and perimeter. 
Hooray for arrays!:  Students will identify prime and composite numbers through arrays. The lesson begins with a fun situational story. 
Oops! What did I do?:  This lesson uses a discovery approach to exploring different errors in various strategies of multiplication. The goal is to help students understand multiplication, not force them into using every strategy. 
I See! Division with the Distributive Property:  In this lesson, students will use visual models to represent division using the distributive property as a strategy. Students will have an understanding of how to decompose numbers in the context of division problems using an area model. 
Multiplying Around the Block:  The students will build upon their understanding of the placevalue system and multiplying using baseten models to build their understanding of multiplying with twodigit by twodigit numbers using area models. They will work with partners during the learning process to help them develop the usage of mathematical language when explaining their thinking and calculations to others. 
Aaron and Anya's Quilt Challenge: Problem Solving and Interpreting Remainders:  In this situational story, Aaron and Anya find a large piece of brightly colored fabric. They decide to cut it into squares to make a quilt. Students will find the area of the fabric by multiplying two digits by two digits. They will explore factors as they figure out the largest quilt square that can be cut for 25 students. There will be fabric left over; students will have to determine and justify remainders based on several different scenarios. Finally, students will create their own quilt square using grid paper. 
Replaced Pitcher:  The students will use mathematical skills and problem solving skills to recommend which current starting pitcher will be replaced once one of the pitchers is back on the active roster for the Miami Marlins. They will write a letter on the computer and print it out to respond to the assistant coach's letter. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Kudos for Kicks  MEA:  In this MEA, students will work in collaborative groups to solve multistep problems with whole numbers and decimals by using different mathematical operations of addition, subtraction, and multiplication. The students will be asked to assist a discount shoe store owner, who is planning a one day sale promotion, to choose a famous brand sneaker to feature for the one day sale. Students will determine which one will bring in more customers, as well as provide the most profit. Students will need to read a data table, rank the famous brand sneakers from 16, calculate the total profit margin per pair, and the total sales potential profit margin determined by the number of sneakers in stock. A twist is added to the problem when additional stock items are added, plus one of the brands is removed and two new brands are added. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Let's Think in Small Units:  In this lesson students will make and complete tables to express larger unit measurements in terms of a smaller unit within one system of units. They will use the chart to make comparisons and explain their reasoning. 
2Digit Array Multiplication:  This lesson explores a conceptual approach to multiplying two 2digit numbers. Students will create, explore, describe and record arrays built with place value pieces. The lesson supplies the understanding that will make multiplying multidigit numbers easy to do. 
Amazing Arrays 3X1 or 1X3:  This lesson is the third lesson in a unit beginning with Amazing Arrays and Amazing Arrays 2X1. 
Chance Product:  Are you trying to deepen your students understanding of 2digit by 2digit multiplication? Then this is the game for you. This game allows students to demonstrate their abilities in multiplication and reasoning. Students will place numbers drawn onto a recording sheet in order to create the largest product possible. 
Loaning Out Laptops:  This engaging MEA introduces students to a company named "Loaning Out Laptops" that needs their help in choosing the best laptops for students to do their schoolwork. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Adventure Falls Bus Purchase:  The school district needs to purchase new buses to transport students. Students will be asked to rank the bus choices based on the data provided. The data provided is: price, year, new/used, and capacity (how many students the buses hold). In the twist, students will be given safety information and must decide how to change their procedure with the new information. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Let's Make a Movie:  Students will add and subtract multidigit whole numbers (through the millions) to compare and contrast movie genres. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Tennis Lessons:  This MEA asks students to take on the job of a tennis pro and decide which factors are most important in choosing a facility to take tennis lessons. Students will perform math calculations, create a twocolumn table for hours and minutes, develop a procedure to rank facilities, and provide written feedback through letters to a parent whose child needs group tennis lessons and writes letters to ask for advice. They will rank their choices from "best to worst" tennis lesson facilities. Students will provide a detailed written explanation for how they decided to rank factors and their solution for rating tennis lesson facilities. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Boxing Math  Using the Area Model for Multiplication:  A common mistake students make when learning to multiply is treating multiplication like addition, and multiplying ones by ones and tens by tens. In this lesson, your students will avoid that mistake as they learn to use the area model to do double digit multiplication. After group practice, students are taught a game to reinforce their learning. 
Hotels: Where to Stay:  This MEA allows students to explore the creation of a model to rank hotels. Students are presented with the first part of the problem and the data which includes cost, meals served, pet friendly, and closeness to highway. They will determine which hotel will receive their highest recommendation. The second part of the task adds two hotels and additional data related to discounts. Students need to apply and test their model and make modifications as needed. All findings are submitted to the client in writing. Students may use this information to plan a family vacation researching which hotels they might stay in as they travel. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Subtraction Attraction:  In this lesson, students will demonstrate fluency in using a standard algorithm to complete story problems involving subtraction with regrouping using multidigit whole numbers. 
Share and Share Alike:  This lesson is an introduction to division and does not include a procedural recording for division. The student will be able to physically model the division of 2, 3, and 4digit dividends with 1digit divisors using objects and base ten blocks and explain the meaning of a remainder.

Amazing Arrays 2X1:  This is a handson lesson for extending and practicing drawing arrays using area models that show a 2digit number times a 1digit number. Students are also required to use the distributive property of multiplication and the equations they represent. 
Array for Charity!:  Students will use array frames to find out how many pennies each of the classes in their school collected for a charity drive. Students will demonstrate and explain the array frame as well as determining how many pennies will go to each of the seven charities for which they have collected pennies. This lesson may be used as part of an introduction to multiplying 2digit x 2digit numbers. 
Party Entertainment:  In this MEA, students will decide which entertainer an owner of an entertainment company should hire. They will base their decisions on information provided on resumes. Students will calculate the cost of hiring the entertainer (multiplication of whole numbers) as well as compare the statistics of their talent competitions and attendance turnout (comparing fractions). Students will write letters to the owner of the entertainment company ranking the entertainers and providing explanation and justification of their strategy for doing so. Model Eliciting Activities, MEAs, are openended, interdisciplinary problemsolving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom. 
Name  Description 
To regroup or not to regroup:  This task presents an incomplete problem and asks students to choose numbers to subtract (subtrahends) so that the resulting problem requires different types of regrouping. This way students have to recognize the pattern and not just follow a memorized algorithmin other words, they have to think about what happens in the subtraction process when we regroup. This task is appropriate to use after students have learned the standard US algorithm. 
Comparing Money Raised:  The purpose of this task is to give students a better understanding of multiplicative comparison word problems with money. 
Comparing Products:  The purpose of this task is to generate a classroom discussion that helps students synthesize what they have learned about multiplication in previous grades. It builds on applying properties of operations as strategies to multiply and divide and interpreting a multiplication equation as a comparison. 
Name  Description 
Hand Spans, A Lesson for Third and Fourth Graders (Division and Measurement):  A measurement activity to give students experience with the grouping model of division and practice with rulers and tape measures. 
Name  Description 
Division: The importance of place value:  In this video tutorial from Khan Academy, learn about the importance of place value when dividing. The tutorial uses place value up to thousands to help students think about division. 
Division: Intro to remainders:  In this video tutorial from Khan Academy, you will get an introduction to the meaning of remainders. 
Multiplying: how to use the area model:  In this video tutorial from Khan Academy, view a demonstration of how to setup an area model for multiplying a twodigit number by a twodigit number on graph or grid paper and then link this to the standard algorithm. 
Multiplying: 2digit number times a 2digit number (area model):  In this tutorial video from Khan Academy, view an example of how to multiply a twodigit number by a twodigit number using the area model. The video makes a connection between partial products and the area model. 
Multiplying: 2digit number times 2digit number (using distributive property):  In this video tutorial from Khan Academy, view an example and a description of how the distributive property can be used to multiply a twodigit number by a twodigit number. The second example uses the area model with the distributive property. 
Multiplying: 4digits times 1digit (using expanded form):  In this Khan Academy video tutorial, view an example of multiplying a 4digit number by a 1digit number by expanding the 4digit number and multiplying by each digit individually in an area model. This video will help to build an understanding before teaching the standard algorithm. Multiplying with a 4digit factor is larger than some standards which limit factors to 3digits. 
Multiplying: 2digit number times a 2digit number (standard algorithm):  In this tutorial video from Khan Academy, view an example of how to multiply a 2digit number by another 2digit number. Be sure to stick around for the second example! The key is understanding the value of each digit! 
Multiplying: 3 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a problem in which a 3digit number is being multiplied by a 1digit number using the standard algorithm. 
Multiplying: 2 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a multiplication problem with a twodigit number multiplied by a onedigit number using the standard algorithm. 
Subtracting: regrouping twice:  In this video tutorial from Khan Academy, learn how to subtract in situations that require regrouping twice using the expanded forms of numbers, as well as the standard algorithm. 
Mental technique for subtraction without regrouping:  In this Khan Academy video tutorial, consider an alternate algorithm for subtracting multidigit numbers mentally. This video is best for students that are already comfortable with using regrouping to subtract using the standard algorithm. 
Subtraction by Regrouping:  This 8minute video demonstrates how to perform subtraction with regrouping. The presenter uses base10 blocks to explain the rationale and to make a visual connection with the standard algorithm. The examples involve 2digit and 3digit numbers. 
Title  Description 
CPALMS Aquarium: Part 3 Division with Larger Numbers:  Learn more about division with larger numbers in this aquariumthemed, interactive tutorial. This is part 3 of in a threepart series. Click below to learn different strategies to help you become more efficient with division. 
CPALMS Aquarium Part 2: Division Strategies:  Learn to solve division challenges using the partial quotients strategy with this interactive tutorial. This is the second tutorial is a series on division strategies. 
CPALMS Aquarium: Connecting Multiplication and Division: Part 1:  Learn how multiplication connects to division to help understand what division is in this aquariumthemed, interactive tutorial. This is part 1 of a twopart series. Click to open Part 2, Division Strategies. 
MultiDigit Multiplication Magic Part 3: Recording Partial Products:  Calculate the product of multidigit factors by decomposing factors and recording partial products in this interactive tutorial. This is part 3 in a 3part series. Click below to open the other tutorials in the series.

MultiDigit Multiplication Area Models: Part 2:  See the magical power of area models when multiplying multidigit numbers in this interactive tutorial. This is part 2 in a 3part series. Click below to open the other tutorials in the series.

MultiDigit Multiplication Magic Part 1: Arrays:  Learn to use arrays to solve multidigit multiplication problems in this interactive tutorial. This is part 1 in a 3part series. Click below to open the other tutorials in the series. 
Adding It All Up with a Standard Algorithm:  Learn to add multidigit numbers using a standard algorithm in this interactive tutorial. 
Title  Description 
Estimator Four:  In this activity, students play a game of connect four, but to place a piece on the board they have to correctly estimate an addition, multiplication, or percentage problem. Students can adjust the difficulty of the problems as well as how close the estimate has to be to the actual result. This activity allows students to practice estimating addition, multiplication, and percentages of large numbers (100s). This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Estimator Quiz:  In this activity, students are quizzed on their ability to estimate sums, products, and percentages. The student can adjust the difficulty of the problems and how close they have to be to the actual answer. This activity allows students to practice estimating addition, multiplication, or percentages of large numbers. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Title  Description 
Arithmetic Quiz:  In this activity, students solve arithmetic problems involving whole numbers, integers, addition, subtraction, multiplication, and division. This activity allows students to track their progress in learning how to perform arithmetic on whole numbers and integers. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet. 
Title  Description 
To regroup or not to regroup:  This task presents an incomplete problem and asks students to choose numbers to subtract (subtrahends) so that the resulting problem requires different types of regrouping. This way students have to recognize the pattern and not just follow a memorized algorithmin other words, they have to think about what happens in the subtraction process when we regroup. This task is appropriate to use after students have learned the standard US algorithm. 
Comparing Money Raised:  The purpose of this task is to give students a better understanding of multiplicative comparison word problems with money. 
Comparing Products:  The purpose of this task is to generate a classroom discussion that helps students synthesize what they have learned about multiplication in previous grades. It builds on applying properties of operations as strategies to multiply and divide and interpreting a multiplication equation as a comparison. 
Title  Description 
Division: The importance of place value:  In this video tutorial from Khan Academy, learn about the importance of place value when dividing. The tutorial uses place value up to thousands to help students think about division. 
Division: Intro to remainders:  In this video tutorial from Khan Academy, you will get an introduction to the meaning of remainders. 
Multiplying: how to use the area model:  In this video tutorial from Khan Academy, view a demonstration of how to setup an area model for multiplying a twodigit number by a twodigit number on graph or grid paper and then link this to the standard algorithm. 
Multiplying: 2digit number times a 2digit number (area model):  In this tutorial video from Khan Academy, view an example of how to multiply a twodigit number by a twodigit number using the area model. The video makes a connection between partial products and the area model. 
Multiplying: 2digit number times 2digit number (using distributive property):  In this video tutorial from Khan Academy, view an example and a description of how the distributive property can be used to multiply a twodigit number by a twodigit number. The second example uses the area model with the distributive property. 
Multiplying: 4digits times 1digit (using expanded form):  In this Khan Academy video tutorial, view an example of multiplying a 4digit number by a 1digit number by expanding the 4digit number and multiplying by each digit individually in an area model. This video will help to build an understanding before teaching the standard algorithm. Multiplying with a 4digit factor is larger than some standards which limit factors to 3digits. 
Multiplying: 2digit number times a 2digit number (standard algorithm):  In this tutorial video from Khan Academy, view an example of how to multiply a 2digit number by another 2digit number. Be sure to stick around for the second example! The key is understanding the value of each digit! 
Multiplying: 3 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a problem in which a 3digit number is being multiplied by a 1digit number using the standard algorithm. 
Multiplying: 2 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a multiplication problem with a twodigit number multiplied by a onedigit number using the standard algorithm. 
Subtracting: regrouping twice:  In this video tutorial from Khan Academy, learn how to subtract in situations that require regrouping twice using the expanded forms of numbers, as well as the standard algorithm. 
Mental technique for subtraction without regrouping:  In this Khan Academy video tutorial, consider an alternate algorithm for subtracting multidigit numbers mentally. This video is best for students that are already comfortable with using regrouping to subtract using the standard algorithm. 
Title  Description 
To regroup or not to regroup:  This task presents an incomplete problem and asks students to choose numbers to subtract (subtrahends) so that the resulting problem requires different types of regrouping. This way students have to recognize the pattern and not just follow a memorized algorithmin other words, they have to think about what happens in the subtraction process when we regroup. This task is appropriate to use after students have learned the standard US algorithm. 
Comparing Money Raised:  The purpose of this task is to give students a better understanding of multiplicative comparison word problems with money. 
Comparing Products:  The purpose of this task is to generate a classroom discussion that helps students synthesize what they have learned about multiplication in previous grades. It builds on applying properties of operations as strategies to multiply and divide and interpreting a multiplication equation as a comparison. 
Title  Description 
Division: The importance of place value:  In this video tutorial from Khan Academy, learn about the importance of place value when dividing. The tutorial uses place value up to thousands to help students think about division. 
Division: Intro to remainders:  In this video tutorial from Khan Academy, you will get an introduction to the meaning of remainders. 
Multiplying: how to use the area model:  In this video tutorial from Khan Academy, view a demonstration of how to setup an area model for multiplying a twodigit number by a twodigit number on graph or grid paper and then link this to the standard algorithm. 
Multiplying: 2digit number times a 2digit number (area model):  In this tutorial video from Khan Academy, view an example of how to multiply a twodigit number by a twodigit number using the area model. The video makes a connection between partial products and the area model. 
Multiplying: 2digit number times 2digit number (using distributive property):  In this video tutorial from Khan Academy, view an example and a description of how the distributive property can be used to multiply a twodigit number by a twodigit number. The second example uses the area model with the distributive property. 
Multiplying: 4digits times 1digit (using expanded form):  In this Khan Academy video tutorial, view an example of multiplying a 4digit number by a 1digit number by expanding the 4digit number and multiplying by each digit individually in an area model. This video will help to build an understanding before teaching the standard algorithm. Multiplying with a 4digit factor is larger than some standards which limit factors to 3digits. 
Multiplying: 2digit number times a 2digit number (standard algorithm):  In this tutorial video from Khan Academy, view an example of how to multiply a 2digit number by another 2digit number. Be sure to stick around for the second example! The key is understanding the value of each digit! 
Multiplying: 3 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a problem in which a 3digit number is being multiplied by a 1digit number using the standard algorithm. 
Multiplying: 2 digits times 1 digit (standard algorithm):  In this video tutorial from Khan Academy, view an example of how to solve a multiplication problem with a twodigit number multiplied by a onedigit number using the standard algorithm. 
Subtracting: regrouping twice:  In this video tutorial from Khan Academy, learn how to subtract in situations that require regrouping twice using the expanded forms of numbers, as well as the standard algorithm. 
Mental technique for subtraction without regrouping:  In this Khan Academy video tutorial, consider an alternate algorithm for subtracting multidigit numbers mentally. This video is best for students that are already comfortable with using regrouping to subtract using the standard algorithm. 