# MA.2.NSO.2.3

Add two whole numbers with sums up to 100 with procedural reliability. Subtract a whole number from a whole number, each no larger than 100, with procedural reliability.

### Examples

Example: The sum 41+23 can be found by using a number line and “jumping up” by two tens and then by three ones to “land” at 64.

Example: The difference 87-25 can be found by subtracting 20 from 80 to get 60 and then 5 from 7 to get 2. Then add 60 and 2 to obtain 62.

### Clarifications

Clarification 1: Instruction focuses on helping a student choose a method they can use reliably.
General Information
Subject Area: Mathematics (B.E.S.T.)
Strand: Number Sense and Operations
Date Adopted or Revised: 08/20
Status: State Board Approved

## Related Courses

This benchmark is part of these courses.
5012040: Mathematics - Grade Two (Specifically in versions: 2014 - 2015, 2015 - 2022, 2022 and beyond (current))
7712030: Access Mathematics Grade 2 (Specifically in versions: 2014 - 2015, 2015 - 2018, 2018 - 2022, 2022 and beyond (current))
5012005: Foundational Skills in Mathematics K-2 (Specifically in versions: 2019 - 2022, 2022 and beyond (current))

## Related Access Points

Alternate version of this benchmark for students with significant cognitive disabilities.
MA.2.NSO.2.AP.3: Apply a strategy for adding and subtracting a two-digit number (from 11 to 19) and a single digit whole number.

## Related Resources

Vetted resources educators can use to teach the concepts and skills in this benchmark.

## Formative Assessments

Differences on a Number Line:

Students use a number line to find to the difference between 17 and 42.

Type: Formative Assessment

Fluently Subtract Within 100:

Students are asked to solve three subtraction within 100 problems and are observed for the use of place value strategies.

Type: Formative Assessment

Adding Within 100 Using Place Value:

Students are asked to solve two addition problems and are observed for the use of place value strategies.

Type: Formative Assessment

Sums on a Number Line:

Students use a number line to add 23 and 19 and to find a segment whose length is the sum of 23 and 19.

Type: Formative Assessment

Using Place Value:

Students are asked to solve a two-digit addition problem using a place value strategy and then are asked to explain why this strategy works.

Type: Formative Assessment

Using Properties and Place Value to Add and Subtract:

Students are asked to complete addition and subtraction problems that can be done efficiently by using properties of operations.

Type: Formative Assessment

The student is asked to solve an addition and a subtraction problem in which a decade (i.e., a multiple of ten) must be crossed.

Type: Formative Assessment

Subtracting Multiples of Ten:

Students find the difference between two multiples of 10.

Type: Formative Assessment

Subtracting Forty:

Students subtract 40 from 80 using linking cubes as a model.

Type: Formative Assessment

Jumping Rope:

Students add a multiple of 10 to a two-digit number.

Type: Formative Assessment

Adding Tens to Numbers:

Students add a multiple of 10 to a two-digit number and are asked to relate the strategy used to a written method.

Type: Formative Assessment

## Lesson Plans

Fundraising on a Budget:

This Model-Eliciting Activity (MEA) is designed for a second grade level. Students will be working in small groups to figure out what companies to hire for the art gallery to have a successful charity event. The students will be evaluating criteria such as bands for the event, caterers, and artists. Students will need to add money to stay within a budget. They will write their procedure for making their selections.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Type: Lesson Plan

Carnival:

Written at a second grade level, in this MEA the students will use problem solving skills, two-digit addition, and knowledge of greater than and less than to rank order carnival games based on provided criteria.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Type: Lesson Plan

This MEA asks students to decide which factors are important in choosing the best cookie in a cookie contest. Students will take on the role of cookie critics to provide feedback to a teacher whose grade level is deciding which cookie to use for a fundraiser. They will rank order their choices from the best to worst cookie. Students will provide a detailed written explanation for how they decided to rank factors and their solution. They will show their work while adding up to 4 two-digit numbers to calculate the total number of votes.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Type: Lesson Plan

Birthday Parties 'R' Us:

Students will determine which pizza place should be used to cater parties at the Birthday Parties 'R' Us facility given a set of data. They will create a procedure for determining the best pizza place, write an explanation about their procedure, and present their recommendations to the class.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Type: Lesson Plan

How Many Inches, Feet, and Yards?:

Students will measure the length of given objects using various measuring tools. The students will record their measurements using different units including inches, feet, and yards to the nearest whole unit. Students will also estimate and measure the lengths of objects, then compare their estimations to their measurements to find the difference.

Type: Lesson Plan

Odds and Evens:

This resource helps students identify numbers as odd or even using a variety of methods including creating pairs, skip counting by two’s, using number lines, and arrays. It also leads them to understand that all even numbers can be written as a sum of equal addends and odds can be written as the sum of equal addends plus one.

This resource can be conducted as one lesson or can be spread over multiple mini sessions if needed as noted within this resource as Lesson 1 and Lesson 2.

Type: Lesson Plan

## Original Student Tutorial

Subtraction with Stanley:

Learn to use place value to solve subtraction problems within 100 in this interactive, basketball-themed tutorial.

Type: Original Student Tutorial

## Tutorials

Subtracting with regrouping:

In this tutorial video from Khan Academy, a subtraction problem is solved which contains two numbers each with two-digits. The video demonstrates subtraction with regrouping using the standard algorithm, as well as a method using expanded form.

Type: Tutorial

Subtracting two-digit numbers without regrouping:

In this video tutorial from Khan Academy, explore subtracting two-digit numbers by using the standard algorithm. This video does not include regrouping.

Type: Tutorial

Adding two-digit numbers without regrouping:

In this tutorial video from Khan Academy, explore adding two-digits numbers with base ten blocks and connect this to the standard algorithm. The examples do not include regrouping.

Type: Tutorial

Understanding place value when subtracting tens:

In this video tutorial from Khan Academy, explore the connection between place value and subtraction. This video explains how to solve a subtraction problem with numbers less than one hundred using base ten blocks.

Type: Tutorial

Understanding place value while adding tens:

Learn how to add 23 + 30 by thinking about place value.

Type: Tutorial

## STEM Lessons - Model Eliciting Activity

Birthday Parties 'R' Us:

Students will determine which pizza place should be used to cater parties at the Birthday Parties 'R' Us facility given a set of data. They will create a procedure for determining the best pizza place, write an explanation about their procedure, and present their recommendations to the class.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Carnival:

Written at a second grade level, in this MEA the students will use problem solving skills, two-digit addition, and knowledge of greater than and less than to rank order carnival games based on provided criteria.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

This MEA asks students to decide which factors are important in choosing the best cookie in a cookie contest. Students will take on the role of cookie critics to provide feedback to a teacher whose grade level is deciding which cookie to use for a fundraiser. They will rank order their choices from the best to worst cookie. Students will provide a detailed written explanation for how they decided to rank factors and their solution. They will show their work while adding up to 4 two-digit numbers to calculate the total number of votes.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

Fundraising on a Budget:

This Model-Eliciting Activity (MEA) is designed for a second grade level. Students will be working in small groups to figure out what companies to hire for the art gallery to have a successful charity event. The students will be evaluating criteria such as bands for the event, caterers, and artists. Students will need to add money to stay within a budget. They will write their procedure for making their selections.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving 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.

## MFAS Formative Assessments

Adding Tens to Numbers:

Students add a multiple of 10 to a two-digit number and are asked to relate the strategy used to a written method.

Adding Within 100 Using Place Value:

Students are asked to solve two addition problems and are observed for the use of place value strategies.

The student is asked to solve an addition and a subtraction problem in which a decade (i.e., a multiple of ten) must be crossed.

Differences on a Number Line:

Students use a number line to find to the difference between 17 and 42.

Fluently Subtract Within 100:

Students are asked to solve three subtraction within 100 problems and are observed for the use of place value strategies.

Jumping Rope:

Students add a multiple of 10 to a two-digit number.

Subtracting Forty:

Students subtract 40 from 80 using linking cubes as a model.

Subtracting Multiples of Ten:

Students find the difference between two multiples of 10.

Sums on a Number Line:

Students use a number line to add 23 and 19 and to find a segment whose length is the sum of 23 and 19.

Using Place Value:

Students are asked to solve a two-digit addition problem using a place value strategy and then are asked to explain why this strategy works.

Using Properties and Place Value to Add and Subtract:

Students are asked to complete addition and subtraction problems that can be done efficiently by using properties of operations.

## Original Student Tutorials Mathematics - Grades K-5

Subtraction with Stanley:

Learn to use place value to solve subtraction problems within 100 in this interactive, basketball-themed tutorial.

## Student Resources

Vetted resources students can use to learn the concepts and skills in this benchmark.

## Original Student Tutorial

Subtraction with Stanley:

Learn to use place value to solve subtraction problems within 100 in this interactive, basketball-themed tutorial.

Type: Original Student Tutorial

## Tutorials

Subtracting with regrouping:

In this tutorial video from Khan Academy, a subtraction problem is solved which contains two numbers each with two-digits. The video demonstrates subtraction with regrouping using the standard algorithm, as well as a method using expanded form.

Type: Tutorial

Subtracting two-digit numbers without regrouping:

In this video tutorial from Khan Academy, explore subtracting two-digit numbers by using the standard algorithm. This video does not include regrouping.

Type: Tutorial

Adding two-digit numbers without regrouping:

In this tutorial video from Khan Academy, explore adding two-digits numbers with base ten blocks and connect this to the standard algorithm. The examples do not include regrouping.

Type: Tutorial

Understanding place value when subtracting tens:

In this video tutorial from Khan Academy, explore the connection between place value and subtraction. This video explains how to solve a subtraction problem with numbers less than one hundred using base ten blocks.

Type: Tutorial

Understanding place value while adding tens:

Learn how to add 23 + 30 by thinking about place value.

Type: Tutorial

## Parent Resources

Vetted resources caregivers can use to help students learn the concepts and skills in this benchmark.

## Tutorials

Subtracting with regrouping:

In this tutorial video from Khan Academy, a subtraction problem is solved which contains two numbers each with two-digits. The video demonstrates subtraction with regrouping using the standard algorithm, as well as a method using expanded form.

Type: Tutorial

Subtracting two-digit numbers without regrouping:

In this video tutorial from Khan Academy, explore subtracting two-digit numbers by using the standard algorithm. This video does not include regrouping.

Type: Tutorial

Adding two-digit numbers without regrouping:

In this tutorial video from Khan Academy, explore adding two-digits numbers with base ten blocks and connect this to the standard algorithm. The examples do not include regrouping.

Type: Tutorial

Understanding place value when subtracting tens:

In this video tutorial from Khan Academy, explore the connection between place value and subtraction. This video explains how to solve a subtraction problem with numbers less than one hundred using base ten blocks.

Type: Tutorial

Understanding place value while adding tens:

Learn how to add 23 + 30 by thinking about place value.

Type: Tutorial