CCSS.Math.Content.1.OA.D

CCSS.Math.Content.1.OA.D is a cluster heading. These are the individual standards under it.

• CCSS.Math.Content.1.OA.D.7

  Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false.

• CCSS.Math.Content.1.OA.D.8

  Determine the unknown whole number in an addition or subtraction equation relating three whole numbers.

01

What Students Need to Do

Students check whether both sides of a number sentence have the same value. They also find a missing number in an addition or subtraction equation.

02

What Mastery Looks Like

Students correctly decide whether addition and subtraction equations are true. They find a missing number in any position and explain how both sides have the same value.

03

Common Misconceptions

Students may think the equal sign means “the answer comes next.” They may judge an equation by its layout instead of checking both sides. Some choose the number named last when finding a missing value.

04

How to Assess It

Exit ticket: Mark 7 = 4 + 3 as true or false, then complete 9 = 5 + __. Ask students to explain one answer.

1. 01

   Give pairs linking cubes and equation cards, then have students build each side and check whether the amounts match.

2. 02

   Write 8 = 5 + 3 and 5 + 3 = 8, then ask students to explain what the equal sign means.

3. 03

   Play Equation Sort by having students place number sentence cards under True or False, then correct each false card.

4. 04

   Present a lunch count with 12 trays and 7 students served, then ask students to write an equation for the trays left.

• CCSS.Math.Content.1.OA.B

  Understand and apply properties of operations and the relationship between addition and subtraction.

• CCSS.Math.Content.2.OA.A

  Represent and solve problems involving addition and subtraction.

• CCSS.Math.Content.1.OA.A

  Represent and solve problems involving addition and subtraction.

• CCSS.Math.Content.K.OA.A.2

  Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.