Standard

Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6 = 6, 7 = 8 - 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2.

Student Language:

• "I can tell if addition or subtraction number sentences are true because I understand what an equal sign means."

Explanation

About the Math, Learning Targets, and Rigor

This standard calls for students to work with the concept of equality by identifying whether equations are true or false. Therefore, students need to understand that the equal sign does not mean “answer comes next”, but rather that the equal sign signifies a relationship between the left and right side of the equation. Interchanging the language of “equal to” and “the same as” as well as “not equal to” and “not the same as” will help students grasp the meaning of the equal sign. Students should understand that “equality” means “the same quantity as”.

In order for students to avoid the common pitfall that the equal sign means “to do something” or that the equal sign means “the answer is,” they need to be able to:

• Express their understanding of the meaning of the equal sign
• Accept sentences other than a + b = c as true (𝑎 = 𝑎, 𝑐 = 𝑎 + 𝑏, 𝑎 = 𝑎 + 0, 𝑎 + 𝑏 = 𝑏 + 𝑎)
• Know that the equal sign represents a relationship between two equal quantities
• Compare expressions without calculating

Provide opportunities for students use objects of equal weight and a number balance to model equations for sums and differences less than or equal to 20 using the numbers 0 to 20.

When asking students to determine whether the equations are true or false have them record their work with drawings. Students then compare their answers as a class and discuss their reasoning. Present equations recorded in a nontraditional way, like 13 = 16 − 3 and 9 + 4 = 18 − 5, then ask, “Is this true?.” Have students decide if the equation is true or false. Then as a class, students discuss their thinking that supports their answers.

Provide situations relevant to first graders for these problem types illustrated in Table 1.

Resources

Videos

• Khan Academy
  • Scroll to 1.OA.6, click on skill, find videos on left side of each skill

Extra Practice

• North Carolina Tasks
• Illustrative Math Tasks
• Howard County Tasks
  • Click on 1st grade at bottom, then 1.OA.6
• Common Core Sheets