3rd grade three-digit addition & subtraction worksheets

Third graders are expected to add and subtract within 1000 fluently, regrouping included. These sheets alternate the two operations so your child reads each sign instead of running on autopilot, the exact skill mixed-operation tests check.

Free printable PDF worksheet, aligned to Common Core 3.NBT.A.2, 4.NBT.B.4.

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The kind of problems you'll get

Add or subtract. Show your work.

916 + 663 =
Answer: 1579
841 + 465 =
102 + 391 =

Every print pulls a fresh set of problems at this level, so a make-up test or a second sibling never gets the same sheet.

What's on each sheet

Computation. Add or subtract. Show your work. 9 questions per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

Accuracy with signs and regroups comes before speed. Ask for an estimate first: 634 − 278 should land near 350, so wild answers get caught on the spot. Check subtraction by adding the answer back up.

Watch for: Kids do whatever the first problem did. These pages alternate, so check each sign before starting. Kids drop the second regroup when a problem needs two. Write every carry or trade above its column.

Common questions about three-digit addition & subtraction

My 3rd grader is fine adding but slow subtracting. Normal?: Very. Borrowing has more steps than carrying. Let them start with the subtraction problems while they're fresh.
Are the numbers different on every print?: Yes. Each print draws a new set of three-digit problems, so practice never repeats.

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Aligned to Common Core 3.NBT.A.2, 4.NBT.B.4. Reviewed by the One more sheet curriculum team. Content version 123, updated July 2026.