MA.K.AR.2.1

Explain why addition or subtraction equations are true using objects or drawings.

Examples

The equation 7=9-2 can be represented with cupcakes to show that it is true by crossing out two of the nine cupcakes.

Clarifications

Clarification 1: Instruction focuses on the understanding of the equal sign.

Clarification 2: Problem types are limited to an equation with two or three terms. The sum or difference can be on either side of the equal sign.
Clarification 3: Addition and subtraction are limited to sums within 20 and related subtraction facts.

General Information
Subject Area: Mathematics (B.E.S.T.)
Grade: K
Strand: Algebraic Reasoning
Date Adopted or Revised: 08/20
Status: State Board Approved

Benchmark Instructional Guide

Connecting Benchmarks/Horizontal Alignment

 

Terms from the K-12 Glossary

  • Equal Sign
  • Equation

 

Vertical Alignment

Previous Benchmarks

Next Benchmarks

 

Purpose and Instructional Strategies

The purpose of this benchmark is to provide explicit opportunities for students to deepen understanding by justifying their solutions and explaining strategies they have chosen, as well as developing an understanding of the equal sign (MTR.6.1, MTR.4.1). 
  • Instruction may present equations in different forms, such as a + b = c or c = a + b (MTR.2.1). 
  • Instruction focuses on understanding and supporting, not only identifying whether or not an equation is true. 
  • Instruction helps students understand that the equal sign does not mean to compute, but relates quantities to one another.
  • Instruction includes the use of context to provide a purpose for adding or subtracting, and to support and scaffold student drawings (MTR.7.1).

 

Common Misconceptions or Errors

  • Students may think that “equals” just means to compute, and may not recognize equations and expressions represented in non-standard ways, such as with pictures or manipulatives.

 

Strategies to Support Tiered Instruction

  • Teacher provides manipulatives to build sets that represent equations and determine if they are true or false.
  • For example, the teacher provides students with the equation 3 + 4 = 7. Students build the addends using two-color counters with the yellow side facing up. Students build the sum with two-color counters with the red side facing up. Teacher asks “Are the two sides of the equation equal? Do they have the same value?” Students should count to find the sum of both sides and record the comparison as 7 = 7. Discussion should focus on the quantities on both sides of the equal sign being the same or different.

addends

  • Instruction includes opportunities to use money manipulatives (dollar bills) to build knowledge of enough.
    • For example, in groups, teacher provides students with eight 1-dollar bills. Teacher provides picture cards with costs labeled of things the students could buy with their eight 1-dollar bills. Teacher asks: Do you have enough money to buy the sticker and the lollipop? Do you have enough money to buy a book and a pencil? Discussion should focus on if the student has enough money to buy the items.
  • Teacher provides a math number balance to explore the equal sign with quantities from 1 to 10.
    • For example, students can build the equation 3 + 2 = 6 and determine if the equation is true.

 

Instructional Tasks

Instructional Task 1 

Decide if each equation is true or false. Draw a picture or write a new equation to defend your answer. 
3 + 7 = 13 
12 = 17 − 5 
7 + 6 = 13 
3+4=7 
7=6+2 
9 = 13 − 3 
12 = 21 

Instructional Task 2 

Lamar says that there are 6 blue marbles and 7 green marbles. Jackie says that there are 13 marbles? Who is right? Draw a picture and write an equation to prove your answer.

 

Instructional Items

Instructional Item 1 

Draw a picture to show that 17 = 7 + 10. 

 

*The strategies, tasks and items included in the B1G-M are examples and should not be considered comprehensive.

Related Courses

This benchmark is part of these courses.
5012020: Grade Kindergarten Mathematics (Specifically in versions: 2014 - 2015, 2015 - 2022, 2022 - 2024, 2024 and beyond (current))
7712015: Access Mathematics - Grade Kindergarten (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 - 2024, 2024 and beyond (current))

Related Access Points

Alternate version of this benchmark for students with significant cognitive disabilities.
MA.K.AR.2.AP.1: Show that an addition or subtraction equation within 5 is true using objects or drawings.

Related Resources

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

Lesson Plans

Balancing Equations:

This is an engaging, hands-on lesson to help the students understand the meaning of the equal sign. The lesson is written using a pan/equal arm balance but may be done with just connecting cubes.

Type: Lesson Plan

Monster Math - Composing and Decomposing the Number 10:

This activity will have students finding ways to make ten. Students use two colors of linking cubes to make and record equations of ten.

Type: Lesson Plan

Perspectives Video: Teaching Idea

Equations on the Math Balance:

Unlock an effective teaching strategy for teaching inequalities and equations with the math balance in this Teacher Perspectives video for educators.

Type: Perspectives Video: Teaching Idea

Student Resources

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

Parent Resources

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