Skip to content
LessonPrint

Add a One-Digit Number with Regrouping is a free printable Grade 1 maths worksheet on adding ones that cross a ten, aligned to Common Core standard 1.NBT.C.4. It prints 16 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.

Next setLesson plan

One paper per pupil

12345678910111213141516171819202122232425

All 25 sets ask different questions.

Add a One-Digit Number with Regrouping

1.NBT.C.4

NameDate

Work out each answer.

1.23 + 39 =
2.39 + 28 =
3.48 + 29 =
4.23 + 58 =
5.44 + 46 =
6.35 + 38 =
7.33 + 57 =
8.34 + 16 =
9.47 + 26 =
10.54 + 38 =
11.59 + 37 =
12.44 + 27 =
13.58 + 49 =
14.46 + 48 =
15.26 + 27 =
16.52 + 58 =

LessonPrint · 1.NBT.C.4 · Set 1 · free to copy for classroom use

Answer key — Add a One-Digit Number with Regrouping

Set 1. Prints on its own sheet.

  1. 1.62
  2. 2.67
  3. 3.77
  4. 4.81
  5. 5.90
  6. 6.73
  7. 7.90
  8. 8.50
  9. 9.73
  10. 10.92
  11. 11.96
  12. 12.71
  13. 13.107
  14. 14.94
  15. 15.53
  16. 16.110

Questions about Add a One-Digit Number with Regrouping

What does the Add a One-Digit Number with Regrouping worksheet cover?

It practises adding ones that cross a ten — 16 questions for Grade 1, all on Common Core 1.NBT.C.4: Add numbers up to 100. The instruction to pupils is “Work out each answer”, and the answer key follows on the next sheet.

Which Common Core standard does Add a One-Digit Number with Regrouping practise?

CCSS.MATH.CONTENT.1.NBT.C.4 — 1.NBT.C.4, in the Number & Operations in Base Ten domain for Grade 1. The published standard reads: “Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10.” The worksheet assesses that standard rather than a paraphrase of it.

What age or grade is this worksheet for?

Add a One-Digit Number with Regrouping is written for Grade 1, typically ages 6-7. It is one of the sheets on 1.NBT.C.4, so it suits any pupil working at that standard — including older pupils revisiting it and younger ones working ahead.

Does Add a One-Digit Number with Regrouping come with an answer key?

Yes. All 16 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 Add a One-Digit Number with Regrouping 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 Add a One-Digit Number with Regrouping free to print and photocopy?

Yes. Add a One-Digit Number with Regrouping, 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.NBT.C.4?

Yes — “Adding Within 100” is a 40-minute Grade 1 plan for 1.NBT.C.4, timed section by section, with the misconceptions to expect and an exit ticket. Add a One-Digit Number with Regrouping is the practice that follows it.

More practice for 1.NBT.C.4

Add numbers up to 100.

Teaching this next? Adding Within 100 is the 40-minute plan for it, with the misconceptions to expect.

All Grade 1 worksheets

Last reviewed 2026-09-05. Aligned to 1.NBT.C.4 of the Common Core State Standards for mathematics.