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3-Digit Addition and Subtraction Worksheets

24 free PDFsUS Letter or A4Answer key includedNo login

3-digit addition and subtraction within 1000, without regrouping, regrouping once and twice, across zeros, with place value strategies and find the mistake pages.

Download the 3-digit addition and subtraction worksheets

3-digit addition

Add 3-digit numbers without regrouping, regrouping the ones, regrouping the tens, and both, plus adding by place value.

3-digit subtraction

Subtract 3-digit numbers without regrouping, regrouping once and twice, across zeros and from 200, 300 … 900, plus subtracting by place value.

Mixed practice and checking

Add or subtract by looking at the sign, then find the mistake in worked problems.

Print at 100% (actual size) for the cleanest tracing lines.

About these 3-digit addition and subtraction worksheets

By the end of 2nd grade, children add and subtract within 1000. The rule is the same as with 2-digit numbers: hundreds with hundreds, tens with tens, ones with ones, and regroup when a place has 10 or more (or not enough). These worksheets go one step at a time.

Start without regrouping, then regroup only the ones, only the tens, and both. Subtraction ends with the trickiest kind: subtracting across a zero, like 503 − 278, where a hundred must be regrouped as tens before there are any tens to regroup as ones. Strategy pages break each number into hundreds, tens and ones.

Most pages come as Sheet A, B and C. Every page has an answer key on page 2 that shows the regrouping, and every page prints in black and white on US Letter or A4.

Standards

  • CCSS.MATH.CONTENT.2.NBT.B.7Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
  • CCSS.MATH.CONTENT.2.NBT.B.9Explain why addition and subtraction strategies work, using place value and the properties of operations.

How to use them

  1. Check that 2-digit regrouping is steady first. If it is not, practice that page for a week before moving on.
  2. Work through the addition pages in order: no regrouping, regroup the ones, regroup the tens, then mixed.
  3. Use Add Hundreds, Tens and Ones to show why the column method works: 300 + 400, 40 + 50 and 1 + 5 are added on their own.
  4. Give Subtract Across Zeros and Subtract From 200, 300 … 900 only after the regroup-once pages are easy.
  5. Finish with the mixed page and Find the Mistake as a check of the whole unit.

Teaching tips

  • Say the place names: 6 ones plus 7 ones is 13 ones, so 1 ten and 3 ones.
  • Across zeros: 503 has no tens. Regroup 1 hundred as 10 tens first, then 1 ten as 10 ones. Now it is 4 hundreds, 9 tens and 13 ones.
  • Estimate first: 489 + 312 is about 500 + 300, so the answer is about 800.
  • Line the digits up under H, T and O. Most 3-digit mistakes are digits in the wrong column.
  • Check subtraction by adding: the answer plus the number taken away gives back the top number.

Questions teachers and parents ask

When do children learn 3-digit addition and subtraction?

The standards for 2nd grade include adding and subtracting within 1000 with models and place value strategies. Many classes finish the written method with regrouping in 2nd grade and practice it again in 3rd grade.

How do you subtract across zeros?

For 503 − 278, there are no tens to regroup. Regroup 1 hundred as 10 tens (4 hundreds, 10 tens, 3 ones), then 1 ten as 10 ones (4 hundreds, 9 tens, 13 ones). Now subtract each place: 13 − 8 = 5, 9 − 7 = 2, 4 − 2 = 2, so 225.

Are there answer keys?

Yes. Every page has an answer key on page 2, with the regrouped digits shown above the problem.