Max Rescues the Space Station: Subtract by Tens!

About this Grade 1 Subtracting Multiples Of 10 Drill

Subtracting multiples of 10 is a foundational skill that helps first graders recognize patterns in our number system and builds confidence with larger numbers. When a child can quickly solve 45 - 10 or 67 - 20, they're developing mental math strategies that make future subtraction easier and faster. This skill bridges the gap between single-digit subtraction (which students learned earlier) and multi-digit problems they'll tackle in second grade. At ages 6-7, children's brains are actively forming connections between concrete objects and abstract numbers, making this an ideal time to practice. Real-world applications include figuring out how many coins remain after spending a dime, or how much time is left after 10 minutes pass. Mastering this concept also boosts number sense—the intuitive feel for how numbers work—which underlies all future math success. Students who practice subtracting multiples of 10 regularly show greater flexibility when solving word problems and working with money.

What your student will practice

• Fluently subtract multiples of 10 from two-digit numbers without counting on
• Recognize that subtracting 10, 20, or 30 changes only the tens place
• Apply subtracting-multiples-of-10 to solve simple word problems
• Use place value understanding to explain subtraction strategies mentally

Common mistakes to watch for

The most common error is that students try to subtract from both digits instead of recognizing the pattern. For example, when solving 34 - 10, a child might incorrectly subtract 1 from both the 3 and the 4, arriving at 23 instead of 24. You'll spot this when looking at their work—answers will be too small by several numbers. Another frequent mistake is counting backward on fingers or using a number line for every problem, which slows fluency and suggests the pattern hasn't clicked yet. If your child is still laboriously counting "34, 33, 32..." instead of instantly knowing "24," they need more practice recognizing that only the tens digit changes.