Addition and Subtraction Within 20 Using Ten as a Benchmark

Build a strong foundation for addition and subtraction fluency with this Addition and Subtraction Within 20 unit. This second grade math resource focuses on helping students use 10 as a benchmark number so they can develop flexible strategies for solving larger math facts.

Students practice making ten, adding ten, using ten to add, and using ten to subtract through a variety of visual models and activities. By learning how to use ten strategically, students gain tools that support fact fluency, mental math, compensation strategies, place value understanding, and future multi-digit addition and subtraction.

What’s Included

This unit includes four focused sections:

• Making ten
• Adding ten
• Using ten to add
• Using ten to subtract

Each section includes:

• Worksheets and no-prep printables
• Ten frame activities
• Number bond activities
• Number line activities
• Cut-and-paste worksheets
• Partner matching cards
• Bar model practice
• Quick checks in three formats

Math Strategies Covered

Students practice addition and subtraction within 20 using visual and strategic models, including:

• Ten frames
• Number bonds
• Number lines
• Bar models
• Making 10
• Adding 10
• Using 10 as a benchmark
• Decomposing numbers
• Using known facts to solve unknown facts

Skills Covered

This resource helps students practice:

• Addition within 20
• Subtraction within 20
• Making ten
• Adding ten
• Using ten to add
• Using ten to subtract
• Building math fact fluency
• Developing automaticity with larger facts
• Strengthening number sense
• Using benchmark numbers
• Understanding part-part-whole relationships
• Preparing for two-digit addition and subtraction
• Explaining math thinking with models

Ways to Use This Resource

Use this addition and subtraction unit for:

• Whole-group math instruction
• Small group lessons
• Response to Intervention, or RtI
• Math centers
• Partner activities
• Independent practice
• Morning work
• Homework
• Spiral review
• Fact fluency practice
• Quick checks and progress monitoring

There are enough materials to introduce concepts during direct instruction, provide guided practice, and revisit the strategies throughout the year as students need review or become ready for deeper understanding.

Why Teachers Love It

Teachers love this unit because it focuses on the power of using 10 as a benchmark number instead of relying only on memorization. Students build flexible thinking and learn strategies they can use again when working with larger numbers.

The mix of no-prep printables, cut-and-paste activities, partner cards, and quick checks makes it easy to differentiate practice, support small groups, and monitor student understanding.

Why Using 10 Matters

In the base-10 number system, understanding how to use 10 is an important step toward math fluency. When students can make ten and use ten to add and subtract within 20, they are better prepared to add and subtract two-digit numbers mentally and use place value strategies with confidence.

This Addition and Subtraction Within 20 unit is a complete second grade math resource for teaching students to make ten, add ten, use ten to add, and use ten to subtract. With no-prep worksheets, ten frames, number bonds, number lines, bar models, cut-and-paste activities, partner matching cards, and quick checks, this resource is perfect for math centers, whole-group lessons, small group RtI, fact fluency practice, and building strong addition and subtraction strategies.