Subtraction facts within 20. Game on.

Subtraction facts within 20 is a grade 1 math skill aligned to Common Core standard 1.OA.C.6: add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Below are 8 practice questions with answers and step-by-step explanations, drawn from the 200 subtraction facts within 20 problems our math games drill.

CCSS 1.OA.C.6200 questions in the bank
Kickoff

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Warm-upeasy

What is 13−813 - 8?

13−8=513 - 8 = 5.

Mid-gameeasy

What is 11−1111 - 11?

11−11=011 - 11 = 0.

Mid-gameeasy

What is 0−00 - 0?

0−0=00 - 0 = 0.

Mid-gameeasy

What is 9−39 - 3?

9−3=69 - 3 = 6.

Mid-gameeasy

What is 12−112 - 1?

12−1=1112 - 1 = 11.

Mid-gameeasy

What is 12−1012 - 10?

12−10=212 - 10 = 2.

Mid-gameeasy

What is 1−01 - 0?

1−0=11 - 0 = 1.

Buzzer beatereasy

What is 9−29 - 2?

9−2=79 - 2 = 7.

Overtime

192 more. Played, not assigned.

The rest of the bank lives inside live head-to-head matches — the placement test finds the right starting difficulty.

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Tests that cover subtraction facts within 20:
i-ReadyISIP MathMAP Growth
Reporting domains for this skill
MAP Growth Math K-2: Number and Operationsi-Ready Grade 1: Operations and Algebraic ThinkingISIP Math Grades PK-5: Computations and Algebraic ThinkingStar Math All grades: number and operations
More Grade 1 skills
Missing addendTen more / ten lessAddition facts within 20All Grade 1 practice →

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