Math Worksheet · Grades 2–3
Three-Digit Addition Worksheet
Printable three-digit addition worksheet for grades 2-3. Students practice 27 items – 12 horizontal three-digit sums, 12 stacked vertical sums, and 3 short word problems – with a reference box that walks through one full example with carrying. Most problems include regrouping in one or both columns. Includes a complete answer key.
Subject
Math
Grades
Grades 2–3
Skill Focus
Three-Digit Addition, addition and subtraction
Lesson Length
20 minutes
Lesson Overview
About this worksheet
Three-digit column addition is a foundational skill that bridges two-digit addition and four-digit (and larger) multi-digit work. This worksheet practices the same skill across horizontal, vertical, and word-problem formats so students learn the column-addition procedure regardless of how a problem is presented on the page.
A reference box at the top of page 1 walks through one full example (358 + 276) one column at a time, showing the two carries that occur in this problem. The reference operands do not appear in any assessed item, so the example teaches the strategy without revealing any answers.
Page 3 is a complete answer key with the operation line for every item, organized by section in a compact two-column grid for easy student self-check or aide spot-check.
How to Use This Lesson
Warm up by reading the reference box aloud and modeling 358 + 276 on a whiteboard one column at a time.
Use Section A (horizontal) for guided pair-share – have students rewrite each problem as a vertical stack on lined paper.
Use Section B (vertical) for independent practice; remind students to write the carry digit small above the next column.
Use Section C (word problems) as a 5-minute exit ticket.
Use the answer key on page 3 for student self-check or aide spot-check.
Pair with the Two-Digit Subtraction with Regrouping Worksheet for a balanced add-and-subtract review.
Printable Resource
A classroom-ready PDF with everything in one printable resource.
Free Member Resource · Printable PDF · 3 pages · Answer Key
Three-Digit Addition Worksheet
Printable three-digit addition worksheet for grades 2-3. Students practice 27 items – 12 horizontal three-digit sums, 12 stacked vertical sums, and 3 short word problems – with a reference box that walks through one full example with carrying. Most problems include regrouping in one or both columns. Includes a complete answer key.
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