Grade 1 · Operations and Algebraic Thinking

CCSS.MATH.CONTENT.1.OA.D.8

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

Read this standard on the official Common Core site

Lessons that teach this standard

• Subtraction and Missing Numbers

  First grade: subtract by finding a missing part, such as 10 − 8 as 8 + ? = 10, and find the missing number in any addition or subtraction sentence.