Grade 3 Three-Digit Addition Worksheets
Start with eight focused practice problems, then use the answer key below to check the worksheet.
Practice Worksheet
Grade 3 Three-Digit Addition Practice
Solve each problem. Show your work.
- 1.601 + 105 = _____
- 2.195 + 103 = _____
- 3.713 + 151 = _____
- 4.676 + 22 = _____
- 5.720 + 147 = _____
- 6.623 + 200 = _____
- 7.700 + 94 = _____
- 8.779 + 0 = _____
Show answer key
- Question 1: 706
- Question 2: 298
- Question 3: 864
- Question 4: 698
- Question 5: 867
- Question 6: 823
- Question 7: 794
- Question 8: 779
Next Steps
Finished the worksheet? Get it checked in seconds
Snap a photo of your child's completed Grade 3 three-digit addition work and Gradulo checks every answer with step-by-step feedback.
Check my workNeed another worksheet?
Log in to generate more Grade 3 three-digit addition worksheets and keep practice going.
About These Worksheets
Grade 3 students build fluency with three-digit addition, including problems that regroup in both the ones and tens columns.
Three-digit addition worksheets extend column addition to numbers in the hundreds, giving students practice adding across three place values at once. These problems mix regrouping and non-regrouping cases so students learn to size up a problem first, rather than assuming every question needs a carry.
Adding three-digit numbers is where the standard algorithm really starts to pay off — mental math and counting strategies become impractical once numbers reach into the hundreds, so students need a dependable written method. These worksheets also introduce students to sums that may require regrouping twice in a row (ones into tens, then tens into hundreds), which is a common stumbling block. Clear column formatting and space for carried digits help students keep their work organized and legible.
Skills Practised
- Adding three-digit numbers using the standard algorithm
- Regrouping across multiple place-value columns in a single problem
- Estimating three-digit sums to check for reasonableness
- Keeping columns aligned by place value in written work
- Solving addition problems with numbers up to 999
Parent Tip: Encourage your child to estimate first by rounding each number to the nearest hundred — if 347 + 256 is roughly 350 + 250 = 600, their exact answer should land close to that.