Addition Within 20 Worksheet

Once your child has mastered addition within 10, the next milestone is adding numbers with sums up to 20. This free printable worksheet gives kindergarten through second grade students the structured practice they need to tackle problems like 8 + 7 = 15, 9 + 6 = 15, and 14 + 3 = 17. These problems introduce the important concept of bridging through 10, where children learn to decompose numbers and regroup to find the answer.

What Does This Worksheet Cover?

This worksheet features a range of addition problems with sums between 11 and 20. Students will encounter both single-digit plus single-digit combinations that cross the ten barrier (such as 7 + 5) and problems where a teen number is increased by a small addend (such as 12 + 4). All problems are presented in horizontal format, and there is ample space for children to write their answers. The variety ensures students practice the full range of addition facts within 20, not just the easier combinations they already know.

Why Addition Within 20 Matters

Fluency with addition facts to 20 is a critical benchmark in early elementary math. These facts form the backbone of multi-digit addition, mental math strategies, and problem-solving skills your child will use throughout their education. When students can quickly recall that 8 + 6 = 14 or that 9 + 9 = 18, they free up working memory for more complex tasks like word problems and multi-step calculations. Standardized math curricula across the country expect students to master these facts by the end of second grade.

How to Use This Worksheet

• Start with what they know: Let your child warm up with a few addition within 10 problems before tackling the harder facts.
• Teach the make-a-ten strategy: Show your child how to break apart one addend to make 10 first. For example, 8 + 5 becomes 8 + 2 + 3, which is 10 + 3 = 13.
• Use a number line or ten frames: Visual tools help children see how numbers combine and cross the ten boundary.
• Practice in short sessions: Five to ten minutes of focused practice daily builds lasting fluency without causing frustration.

Tips for Parents and Educators

Children who struggle with addition within 20 often need more time with the make-a-ten strategy. Use real objects grouped into tens and ones to make the concept concrete. Encourage your child to explain their thinking aloud, which strengthens understanding. Once they show confidence with these facts, move on to subtraction within 20 to practice the inverse operation and deepen their number sense.