CCSS 1.OA.8 Worksheets

CCSS 1.OA.8 (Common Core, 1st Grade): "Determine the unknown whole number in an addition or subtraction equation relating to three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ?- 3, 6 + 6 = ?." The worksheets below practice this standard. Each one is a free printable PDF with an answer key, comes in multiple versions, and can also be assigned digitally - no login or account needed.