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Count On Within 20 is a free printable Grade 1 maths worksheet on counting on with a larger start, aligned to Common Core standard 1.OA.C.5. 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 1 of 25 · the same problems every time you open this link.

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One paper per pupil

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All 25 sets ask different questions.

Count On Within 20

1.OA.C.5

NameDate

Work out each answer.

1.10 + 11 =
2.10 + 8 =
3.12 + 12 =
4.10 + 12 =
5.10 + 9 =
6.11 + 11 =
7.10 + 10 =
8.12 + 10 =
9.12 + 11 =

LessonPrint · 1.OA.C.5 · Set 1 · free to copy for classroom use

Answer key — Count On Within 20

Set 1. Prints on its own sheet.

  1. 1.21
  2. 2.18
  3. 3.24
  4. 4.22
  5. 5.19
  6. 6.22
  7. 7.20
  8. 8.22
  9. 9.23

Questions about Count On Within 20

What does the Count On Within 20 worksheet cover?

It practises counting on with a larger start — 9 questions for Grade 1, all on Common Core 1.OA.C.5: Count on to add, and count back to subtract. The instruction to pupils is “Work out each answer”, and the answer key follows on the next sheet.

Which Common Core standard does Count On Within 20 practise?

CCSS.MATH.CONTENT.1.OA.C.5 — 1.OA.C.5, in the Operations & Algebraic Thinking domain for Grade 1. The published standard reads: “Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).” The worksheet assesses that standard rather than a paraphrase of it.

What age or grade is this worksheet for?

Count On Within 20 is written for Grade 1, typically ages 6-7. It is one of the sheets on 1.OA.C.5, so it suits any pupil working at that standard — including older pupils revisiting it and younger ones working ahead.

Does Count On Within 20 come with an answer key?

Yes. All 9 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.

How many different versions of Count On Within 20 can I print?

25 — one per pupil, and all 25 ask different questions. Set 1 downloads the whole class as a single PDF. Every version is fixed to its own address, so a sheet printed today holds the same problems when you reopen it next week.

Is Count On Within 20 free to print and photocopy?

Yes. Count On Within 20, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.

Is there a lesson plan to teach 1.OA.C.5?

Yes — “Counting On and Counting Back” is a 40-minute Grade 1 plan for 1.OA.C.5, timed section by section, with the misconceptions to expect and an exit ticket. Count On Within 20 is the practice that follows it.

More practice for 1.OA.C.5

Count on to add, and count back to subtract.

Teaching this next? Counting On and Counting Back 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.C.5 of the Common Core State Standards for mathematics.