Math Worksheet · Grades 1–2
Adding Three Numbers Worksheet
Printable addition worksheet for grades 1-2 focused on adding three numbers at a time. Students practice 12 horizontal three-addend facts and 8 stacked three-addend problems using make-a-ten, doubles, and known-fact strategies. Includes a complete answer key.
Subject
Math
Grades
Grades 1–2
Skill Focus
Adding Three Numbers, addition and subtraction
Lesson Length
15 minutes
Lesson Overview
About this worksheet
Adding three numbers is a foundational fluency that bridges single-digit addition and multi-digit column addition. This worksheet practices the skill in horizontal and stacked formats so students learn that the same fact families look the same whether read left-to-right or stacked.
A reference box at the top of page 1 teaches students to look for the easiest pair first – two numbers that make 10, a double they already know, or two numbers they’re confident with – and then add the third number to that pair’s sum.
Page 2 is a complete answer key showing the sum for each item, organized by section in a compact two-column grid so students or aides can spot-check quickly.
How to Use This Lesson
Warm up by reading the reference box aloud and modeling the make-a-ten strategy on one Section A item.
Time Section A as a 3-minute fluency check if students are ready.
Use Section B for guided stacked-addition practice; have students annotate which pair they added first.
Use the answer key on page 2 for student self-check or aide spot-check.
Pair with Adding Within 20 Worksheet for additional fact-fluency practice.
Printable Resource
A classroom-ready PDF with everything in one printable resource.
Full Member Resource · Printable PDF · 2 pages · Answer Key
Adding Three Numbers Worksheet
Printable addition worksheet for grades 1-2 focused on adding three numbers at a time. Students practice 12 horizontal three-addend facts and 8 stacked three-addend problems using make-a-ten, doubles, and known-fact strategies. Includes a complete answer key.
This is a Full Member resource
Unlock this worksheet — plus 1,000+ printable worksheets with answer keys across every subject and grade K–12. Just $29.99/year, cancel anytime.
See membership options →Keep Exploring Math
Related Worksheets
More for Grades 1–2Identifying 2D Shapes Worksheet · Identifying Coins Worksheet · Place Value to Hundreds Worksheet · Telling Time to the Hour and Half Hour Worksheet · Telling Time to the Quarter Hour Worksheet · AM and PM Worksheet