🔢Math Standard
3-Digit Addition with Regrouping Worksheet
Add three-digit numbers that require carrying into the tens and hundreds.
3rd Grade 15 min
✓ Answer key
3rd Grade · Math
3rd Grade Addition Worksheets
Third graders add numbers up to 1,000 and learn to choose the right strategy: regrouping on paper or mental-math shortcuts. These free printable 3rd grade addition worksheets build fluency with multi-digit addition, then apply it to real word problems. Every worksheet includes a printable answer key, and the easy, standard, and challenge tiers let you differentiate for small groups, homework, or fast finishers.
Reviewed by ClassReady Editorial Team Last updated August 2026
Before this skill
- Addition facts to 20
- 2-digit addition with regrouping
- Place value to the hundreds
Common mistakes to watch for
- Forgetting to carry the regrouped ten
- Adding columns without aligning place values
- Rushing mental math and dropping a ten
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Frequently Asked Questions
What addition skills do 3rd graders practice?
Third graders add numbers up to 1,000 with regrouping, use mental-math strategies such as compensation and friendly numbers, and solve addition word problems with two steps.
Are these addition worksheets free and printable?
Yes. Every worksheet is a free, printable PDF with an answer key, and no sign-up is required.