Mixed 3-Digit Addition and Subtraction Worksheets for 3rd Grade

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Grade 3MathMixed Math PracticeCCSS 3.NBT.A.2

Skill: 3-digit addition and subtraction with regrouping, mixed on one page

Preview of the Mixed 3-Digit Addition and Subtraction printable worksheet
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Teaching tips and what to try next

Mixing addition and subtraction within 1,000 means children need to notice each sign and regroup in the right direction. A quick estimate first (round to the nearest hundred) catches most slips. For focused practice, try Three-Digit Addition With Regrouping and Three-Digit Subtraction With Regrouping.

10 versions, each with its own answer key

Same skill and layout, a fresh set of problems in every version, so children can keep practicing without repeating a page. Problems are not repeated between versions unless a skill has only a small number of possible problems (for example, the addition facts within 10).

Download all 10 versions (one PDF)All 10 answer keys (PDF)

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About this worksheet

This third grade worksheet mixes 10 three-digit addition problems and 10 three-digit subtraction problems, written in columns under a simple row of leaves, apples, acorns and stars. Every sum stays under 1,000, every difference is positive, and almost every problem needs regrouping in the ones place, the tens place or both.

Because the two operations are mixed, children have to check each sign before they start. That small habit catches many of the mistakes third graders make on tests. Each of the 10 versions has new problems, so there is plenty of practice for a week of warm-ups or homework.

How to use it: have your child estimate first by rounding each number to the nearest hundred, so they know roughly what the answer should be. Then work right to left, one place at a time. When subtracting across a zero, such as 503 - 278, it helps to trade from the hundreds to the tens and then from the tens to the ones. After each subtraction, check by adding the answer to the bottom number.

The answer key shows every answer in red. For more practice, see our 3-Digit Addition and 3-Digit Subtraction worksheets.