CCSS.Math.Content.1.OA.A

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

• CCSS.Math.Content.1.OA.A.1

  Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, wit...

• CCSS.Math.Content.1.OA.A.2

  Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using objects, drawings, and equations with a ...

01

What Students Need to Do

Students make sense of story situations with joining, separating, and comparing quantities. They use objects, drawings, and equations to find a missing number within 20.

02

What Mastery Looks Like

Students use objects, drawings, or equations to show what happens in a story. They find an unknown in any position and explain why their answer fits the situation.

03

Common Misconceptions

Students may choose an operation from a keyword instead of the story. They may assume the unknown always comes last or treat the equal sign as a signal to calculate.

04

How to Assess It

Exit ticket: “There are 13 birds. Some fly away. Eight remain. Draw a model, write an equation, and find how many flew away.”

1. 01

   Give pairs 20 counters and story cards, then have them build each situation and record a matching equation.

2. 02

   Ask, “How can 8 + 5 = 13 help solve 13 − 8?” Students draw and explain their thinking.

3. 03

   Play Equation Match by pairing story cards with model cards and equation cards, including unknowns in different positions.

4. 04

   Set up a classroom store where students solve how many items were bought, remain, or are needed using price-free item counts.

• CCSS.Math.Content.2.OA.A

  The 2nd Grade version of this standard.

• CCSS.Math.Content.1.OA.D

  Work with addition and subtraction equations.

• CCSS.Math.Content.3.OA.A

  Represent and solve problems involving multiplication and division.

• 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.