General Information
Subject Area: Mathematics (B.E.S.T.)
Grade: 2
Strand: Number Sense and Operations
Date Adopted or Revised: 08/20
Status: State Board Approved
Benchmark Instructional Guide
Connecting Benchmarks/Horizontal Alignment
Terms from the K-12 Glossary
- NA
Vertical Alignment
Previous Benchmarks
Next Benchmarks
Purpose and Instructional Strategies
The purpose of this benchmark is to extend the work done in grade 1 with two-digit numbers to find the number that is 10 more or 10 less, 100 more or 100 less than a given three-digit number.- Instruction includes encouraging students to use additive reasoning to determine patterns for identifying a number that is 10 more, 10 less, 100 more or 100 less.
- Instruction supports helping students make a connection to the position of a digit within a multi-digit number.
- Instruction includes the use of a hundreds and thousands chart or a number line.
- Instruction is not intended to focus on addition and subtraction strategies.
Common Misconceptions or Errors
- Students may incorrectly assume ten more, ten less, one hundred more and one hundred less can only be applied to multiples of ten.
- Students may have difficulty determining 10 more or 10 less than a three-digit number, especially when combining tens to make a hundred or decomposing a hundred into tens.
- For example, students may not be able to determine that 10 more than 192 is 202. Utilizing a number line or chart may be helpful in visualizing this.
Strategies to Support Tiered Instruction
- Instruction includes the use of place value cards, base-ten blocks, and/or a place value chart. Students build a three-digit number using the place value cards and identifies numbers that are 10 more, 10 less, 100 more, and 100 less. Then, students relate the base ten manipulatives to the place value cards.
- For example, using the place value cards for the number 428, build the number. Then, separate your number into expanded form showing 400, 20, and 8. Then, the teacher asks students which value would you change if we were making a number 10 more or 10 less? [20]. The teacher asks, “Which value would you change if we were making a number 100 more or 100 less?” [400]. Create the different numbers that are 10 more, 10 less, 100 more, or 100 less with 428.
- Instruction includes the use of place value cards and base ten blocks, and/or a place value chart. Students build a three-digit number using the cards that has a value of 9 in the tens place. Then, students identify the values of 10 more, 10 less, 100 more, and 100 less. They may have difficulty knowing how to exchange the 10 tens to the next hundred.
- For example, using base ten blocks and place value cards have students build 293. Have students represent 10 more, 10 less, 100 more, and 100 less. Students will need to exchange the 10 tens for 1 hundred when creating 10 more. If students have difficulty, the teacher asks, “How many tens are in 100?” “How many tens in 200?”
Instructional Tasks
Instructional Task 1 (MTR.2.1)
Melanie is thinking of a number. Her number is one hundred more than 456. One student found the solution by adding 100 + 456. Use place value cards to show another way to find Melanie's number.
Enrichment Task 1 (MTR.5.1)
A series of numbers is written below. What is the missing number? Complete the statement to identify how each number changes.234, 244, 254,__
Each number in the series is ________ more than the previous number.
Enrichment Task 2 (MTR.5.1)
Repeat the previous task with the following series of numbers:766,776,786,__,__
Instructional Items
Instructional Item 1
Determine whether the number in column A is 10 more, 10 less, 100 more or 100 less than the number in column B. Write your response in column C.
*The strategies, tasks and items included in the B1G-M are examples and should not be considered comprehensive.