Subtraction within 20 is a cornerstone skill for first graders, helping them understand how quantities decrease, compare, and relate to addition. In Grade 1, children move beyond simple take-away problems with small numbers and begin working with teen numbers, which often requires crossing back over ten.
Two common stumbling blocks at this stage are confusing the order of numbers in a subtraction sentence and miscounting when bridging ten (for example, solving 14 - 6). Kindergarten introduced subtraction within 10 using objects and pictures, and second grade will extend these ideas to two-digit subtraction with regrouping, so fluency now makes that jump much smoother.
Our subtraction within 20 worksheets give first graders varied practice through equations, missing-number puzzles, true-or-false checks, matching, multiple choice, and short word problems. Each page builds confidence by mixing familiar facts with gentle challenges, so children develop both speed and number sense. Regular practice helps first graders recognize fact families, use known sums to find differences, and feel ready for the bigger numbers ahead.
Worksheet Preview
Browse all 12 printable worksheets below — click any card to open the full page.
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
Subtraction Within 20
What's Included in This Download
What You'll Learn
These subtraction within 20 worksheets help grade 1 students develop essential math skills through engaging activities.
Learning Objectives
- Subtraction within 10
- Counting back
- Subtraction fact fluency
- Number sentences
Skills Covered
How to Use These Worksheets
- Download & Print: Click the download button to get the PDF. Print on standard 8.5" x 11" paper.
- Start Simple: Begin with easier pages before moving to more challenging activities.
- Daily Practice: Dedicate 10-15 minutes each day for consistent learning.
- Use Manipulatives: Pair worksheets with physical objects like blocks or counters.
- Provide Encouragement: Celebrate progress and effort to build confidence.
- Check Progress: Use the included answer key to review work together.
Common Mistakes to Watch For
- Reversing the numbers in a subtraction sentence — first graders often see 4 - 9 and solve it as 9 - 4 because they know subtraction 'takes away' but not yet that order matters.
- Miscounting when crossing ten, such as solving 13 - 5 by counting back on fingers and landing on 9 instead of 8 because they include the starting number.
- Forgetting the link between addition and subtraction, so a child who easily knows 8 + 7 = 15 still struggles to see that 15 - 7 = 8 without recounting from scratch.
Frequently Asked Questions
Why is subtraction within 20 harder than subtraction within 10?
Subtraction within 20 introduces teen numbers, which means children must often cross back over ten to find the answer. For example, 14 - 6 requires understanding that you take 4 to reach 10, then 2 more to reach 8. This 'bridging ten' step is a new mental move that takes practice beyond simple take-away facts.
Should my first grader memorize subtraction facts or use strategies?
Both matter, but strategies come first. Grade 1 children should learn to count back, use doubles, and connect subtraction to addition before drilling for memorization. Once strategies feel natural, the facts will stick on their own. Pure memorization without understanding tends to fade quickly and leaves kids stuck when problems look unfamiliar.
What is a fact family and why does it help with subtraction?
A fact family is a group of related addition and subtraction sentences using the same three numbers, such as 7 + 8 = 15, 8 + 7 = 15, 15 - 7 = 8, and 15 - 8 = 7. Teaching fact families helps first graders use addition they already know to solve subtraction quickly, instead of recounting every time.
How can I help my child stop reversing subtraction problems?
Use real objects and language like 'we start with this many, then take some away.' Always read the problem left to right and point to the bigger number first. Practicing with story problems helps too, because the context makes it clear which number is the starting amount and which is being removed.
When will my first grader be ready for subtraction with regrouping?
Most children are ready for two-digit subtraction with regrouping in Grade 2, after they are fluent with subtraction within 20. Mastering facts to 20, especially those that cross ten, builds the mental model needed for borrowing later. If your child still counts on fingers for 13 - 5, focus on within-20 fluency before moving on.
Are these worksheets really free?
Yes! All our worksheets are 100% free to download and print. There's no subscription, no hidden fees, and no registration required.
Can I use these in my classroom?
Absolutely! Teachers are welcome to print and use these worksheets in their classrooms. Make as many copies as needed for your students.