Max Conquers the Soccer Field: Subtract by Tens!

About this Grade 1 Subtracting Multiples Of 10 Drill

Subtracting multiples of 10 is a cornerstone skill for Grade 1 because it builds number sense and prepares students for place value understanding. When children learn that 45 – 10 = 35, they're not just memorizing—they're discovering that the ones digit stays the same while the tens digit changes. This mental math strategy helps them work with larger numbers confidently and quickly, whether they're counting soccer jerseys in a bin or calculating change at a store. Mastering this skill also reduces the cognitive load for future subtraction, freeing up mental energy for more complex problems. At ages 6–7, students' brains are primed to recognize patterns, and multiples of 10 offer a clear, repeatable pattern that builds automaticity and mathematical thinking.

What your student will practice

• Recognize that subtracting 10 changes only the tens place
• Solve subtraction problems with multiples of 10 (10, 20, 30, etc.) fluently
• Explain why the ones digit remains unchanged when subtracting 10
• Apply tens subtraction to two-digit numbers without regrouping

Common mistakes to watch for

Many first graders incorrectly subtract from the ones place when they see a problem like 37 – 10, arriving at 36 – 10 = 26 instead of the correct 27. Others mix up the direction of change and add instead of subtract, especially if they're still building automaticity with 10. Watch for students who use their fingers to count backward by ones from 37 all the way to 27—while this shows effort, it indicates they haven't yet internalized the pattern. If you see these errors, gently guide them back to the tens place and remind them: 'Only the tens number changes.'