Max Rescues Submarines: Subtract Multiples of 10!

About this Grade 2 Subtracting Multiples Of 10 Drill

Subtracting multiples of 10 is a foundational skill that helps second graders recognize patterns and build mental math fluency. When students can quickly subtract 10, 20, 30, or 40 from two-digit numbers, they develop number sense and confidence with larger calculations. This skill directly supports their understanding of place value—seeing that 45 - 20 is really just taking away 2 tens while keeping the 5 ones in place. Children this age are moving beyond counting on their fingers, and mastering this concept lets them work faster and more independently. Real-world situations like managing classroom supplies, calculating money at a pretend store, or figuring out how many stickers remain after giving some away all rely on this mental math ability. By practicing subtracting multiples of 10, students build a bridge toward two-digit subtraction and eventually more complex arithmetic.

What your student will practice

• Subtract multiples of 10 from two-digit numbers with automaticity
• Recognize that only the tens place changes when subtracting tens
• Apply place value understanding to solve subtraction problems quickly
• Build mental math strategies independent of counting or manipulatives

Common mistakes to watch for

Many second graders mistakenly subtract the tens digit incorrectly—for example, solving 37 - 20 as 17 instead of 17. They often forget the ones place stays the same and try to subtract from the whole number as if it were a single entity. Another common error is borrowing or regrouping when it isn't needed; students may look at 32 - 10 and feel confused because they learned regrouping rules but don't recognize this problem doesn't need them. Watch for students who lose track of which digit represents tens and which represents ones, or who count backward by ones instead of recognizing the tens pattern.