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Turn It Around — Adding to 20 is a free printable Grade 1 maths worksheet on commutativity across ten, shown as a pair, aligned to Common Core standard 1.OA.B.3. It prints 9 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two pupils in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.

Set 21 of 25 · the same problems every time you open this link.

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One paper per pupil

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Set 1 has all 25 in a single PDF. All 25 sets ask different questions.

Turn It Around — Adding to 20

1.OA.B.3

NameDate

Fill in both blanks.

1.8 + 6 = ___ , so 6 + 8 = ___
2.6 + 7 = ___ , so 7 + 6 = ___
3.7 + 6 = ___ , so 6 + 7 = ___
4.9 + 8 = ___ , so 8 + 9 = ___
5.9 + 7 = ___ , so 7 + 9 = ___
6.8 + 7 = ___ , so 7 + 8 = ___
7.7 + 9 = ___ , so 9 + 7 = ___
8.8 + 9 = ___ , so 9 + 8 = ___
9.6 + 9 = ___ , so 9 + 6 = ___

LessonPrint · 1.OA.B.3 · Set 21 · free to copy for classroom use

Answer key — Turn It Around — Adding to 20

Set 21. Prints on its own sheet.

  1. 1.14 and 14
  2. 2.13 and 13
  3. 3.13 and 13
  4. 4.17 and 17
  5. 5.16 and 16
  6. 6.15 and 15
  7. 7.16 and 16
  8. 8.17 and 17
  9. 9.15 and 15

More practice for 1.OA.B.3

Use facts you know to work out ones you do not — like knowing 3+8 because you know 8+3.

Teaching this next? Using Known Facts to Add is the 40-minute plan for it, with the misconceptions to expect.

All Grade 1 worksheets

Last reviewed 2026-09-05. Aligned to 1.OA.B.3 of the Common Core State Standards for mathematics.