Max Conquers the World Games: Subtraction Speed Challenge!

About this Grade 2 Subtracting Multiples Of 10 Drill

Subtracting multiples of 10 is a foundational skill that builds your second grader's number sense and prepares them for two-digit subtraction. At ages 7-8, students are developing the mental math strategies they'll use throughout elementary math. When children can quickly subtract 10, 20, or 30 from a number, they're recognizing that the ones place stays the same while only the tens place changes. This concept appears everywhere in daily life—when a store reduces a toy's price by 20 dollars, when a student loses 10 points on a game, or when planning snacks for a classroom party. Mastering this skill also boosts confidence because students see they can do subtraction without counting on their fingers, making math feel more efficient and manageable.

What your student will practice

• Subtract multiples of 10 from two-digit numbers with automaticity
• Recognize that only the tens digit changes when subtracting multiples of 10
• Apply subtraction of multiples of 10 to solve one-step word problems
• Use mental math strategies to check subtraction answers

Common mistakes to watch for

The most common error is when students subtract the multiple of 10 incorrectly by treating it like a regular two-digit subtraction problem. For example, a child might subtract 45 − 20 and answer 15 instead of 25, forgetting that the ones digit (5) stays put. Another frequent mistake is reversing digits: answering 42 − 10 = 32 instead of 42 − 10 = 32. Parents and teachers can spot this by asking the student to explain what happened to the ones place—a correct understanding will show the student knows it doesn't change.