Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Number and Operations in Base Ten

Use place value understanding and properties of operations to add and subtract.

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Number and Operations in Base Ten

Use place value understanding and properties of operations to add and subtract.

NGA Center/CCSSO

Last updated:

6/3/2010

- Number and Operations in Base 10
- Elementary (Grades K-2)

Common Core

Included in this activity is a 1-100 chart, 5 puzzles that students will put together and a recording sheet. Students will lay the puzzle piece down...

- Multiple Subjects
- Math
- Number and Operations in Base 10

- K-2, 3-5

Common Core

Random ‘100’ square. Based on the principles of addition and subtraction using a 100 square. This small grid is a snapshot of a full 100 square grid...

- Multiple Subjects
- English Language Arts
- Math

- Elementary (Grades K-2)

Common Core

This lesson demonstrates the importance of showing respect for other people’s belongings. The 2-minute video uses animated characters to model the...

- This standard is part of: CCSS.Math.Content.1.NBT.C

Standards with the same topic and subject but for other grades

Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

19 lessons are aligned with this standard

NGA Center/CCSSO

Last updated:

6/11/2010

Add up to four two-digit numbers using strategies based on place value and properties of operations.

5 lessons are aligned with this standard

NGA Center/CCSSO

Last updated:

6/4/2010

Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.

8 lessons are aligned with this standard

NGA Center/CCSSO

Last updated:

6/10/2010

Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.

5 lessons are aligned with this standard

NGA Center/CCSSO

Last updated:

6/4/2010

Explain why addition and subtraction strategies work, using place value and the properties of operations.

3 lessons are aligned with this standard

NGA Center/CCSSO

Last updated:

6/4/2010

State-specific standards derived from this one

Mentally find 10 more or 10 less than a given two-digit number without having to count by ones and explain the reasoning used.

Tennessee DOE

Last updated:

2/11/2021

North Carolina DOE

Last updated:

6/23/2015

Mentally add or subtract 10 to or from a given two-digit number. Explain the reasoning used.

North Dakota DOE

Last updated:

5/4/2017

Vermont DOE

Last updated:

6/21/2013

Rhode Island DOE

Last updated:

6/20/2013

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