10 printable sets · answer key on every set

Addition With Regrouping to 20 Worksheets

CCSS 1.OA.C.6
20 problems per set
Answer key included

What this skill is

Adding within 20 when the ones cross a ten — 8 + 5, 7 + 6.

When it comes up: Middle of first grade.

The mistake to watch for

Counting on from the smaller number (5 + 8 counted as five, then eight steps), which is slow and error-prone.

How to help

Teach make-a-ten: for 8 + 5, take 2 from the 5 to fill the 8 up to 10, then add the remaining 3. Ten plus three is instant.

Next: Subtraction with borrowing to 20.

A worked example

Try 8 + 5. Make a ten first: 8 needs 2 more to reach 10, so take 2 from the 5. Now you have 10 + 3 = 13.

Words to know

regroup: To trade 10 ones for 1 ten (or 1 ten for 10 ones) when you add or subtract.
ten: The number 10, one more than nine.
add: To put numbers together to find how many in all.
sum: The answer you get when you add.
total: All of the things added together.

Practice

Add. Regroup when you need to.

Showing Set 1 · 20 problems

19 + 1 =
7 + 5 =
9 + 5 =
18 + 2 =
7 + 3 =
8 + 12 =
16 + 4 =
3 + 8 =
4 + 8 =
17 + 3 =
3 + 9 =
7 + 6 =
9 + 9 =
7 + 9 =
1 + 19 =
15 + 5 =
7 + 4 =
8 + 9 =
8 + 7 =
8 + 8 =

Download this set20 problems · answer key included PDF

Answer key

All 10 sets

Each set is a different list of 20 problems with its own answer key. Use the buttons above to look at one on this page, or download any of them as a PDF.

How these sheets were made

Problems are generated for each set and checked against 1.OA.C.6 before the sheet is built — no duplicates, and every problem falls inside the standard's number range.