Max Rescues Fish: Subtract Multiples of 10!

About this Grade 1 Subtracting Multiples Of 10 Drill

Subtracting multiples of 10 is a cornerstone skill that helps first graders build number sense and mental math flexibility. When children learn to subtract 10, 20, or 30 from numbers like 45 or 67, they're recognizing that the ones place stays the same while only the tens change—a pattern that makes math feel logical rather than mysterious. This skill is crucial because it bridges single-digit subtraction (which they've already practiced) to larger numbers, preparing them for multi-digit computation in second grade. At ages 6 and 7, children's brains are developing stronger abstract thinking, and working with tens helps them visualize quantities in groups. Beyond the classroom, this skill appears naturally when kids count money, track scores during games, or help subtract items while fishing or shopping. Mastering this concept builds confidence and shows students that math follows predictable rules.

What your student will practice

• Subtract multiples of 10 from two-digit numbers using tens and ones language
• Recognize that subtracting tens only changes the tens place, not ones
• Apply subtraction with multiples of 10 to solve simple word problems
• Build fluency with facts like 50 − 20 and 73 − 10 without counting on fingers

Common mistakes to watch for

The most common error is when first graders subtract 10 and accidentally change both the tens and ones digits—for example, solving 34 − 10 as 23 instead of 24. This happens because they haven't yet internalized that only the tens place shifts. You'll spot this when a child subtracts 10 and the ones digit mysteriously changes. Another frequent mistake is counting backward by ones instead of by tens, turning a quick mental task into slow, error-prone finger counting. Ask your child to explain which digit changes, and watch whether they're using a tens frame or number line to keep track.