Max Rescues the Chess Kingdom: Subtraction Sprint

About this Grade 1 Subtraction Within 20 Drill

Subtraction within 20 is a cornerstone skill that helps first graders make sense of the world around them. At ages 6 and 7, children are naturally curious about "taking away"—whether it's eating cookies from a plate, giving toys to a friend, or noticing there are fewer apples in a bowl. Mastering these problems builds number sense, mental flexibility, and confidence with basic facts they'll use every day. This skill also strengthens a child's ability to think backward from a number, which is essential for later problem-solving. When students can quickly subtract 7 from 15 or figure out 12 – 5 without counting on their fingers, they free up mental energy for more complex math. These fluent subtraction facts are the building blocks for addition, word problems, and all future math learning.

What your student will practice

• Subtract single-digit numbers from numbers 10–20 fluently
• Use strategies like counting back or decomposing to solve subtraction problems
• Recognize subtraction as "taking away" or "finding the difference" in real contexts
• Develop automaticity with common subtraction facts within 20

Common mistakes to watch for

Many first graders count incorrectly when solving subtraction by forgetting which number they're counting back from. For example, a child solving 14 – 3 might say "13, 12, 11" and then lose track of whether 11 is the answer or needs one more step. Another frequent error is reversing the numbers—solving 5 – 12 instead of 12 – 5. Watch for hesitation or finger-counting on every single problem; this signals the child hasn't yet internalized the fact and may need more concrete practice with objects or drawings before moving to abstract numbers.