Max Rescues Lost Pilots: Subtraction with Borrowing

About this Grade 3 Subtraction With Borrowing Drill

Subtraction-with-borrowing (also called regrouping) is a critical step in your child's math journey because it bridges the gap between simple subtraction facts and real-world problem-solving. At ages 8–9, students are developing their understanding of place value—tens and ones—and this skill forces them to think flexibly about how numbers break apart and come back together. When your child borrows from the tens place to solve a problem like 32 − 15, they're not just getting an answer; they're building number sense and logical reasoning that will support multi-digit subtraction, division, and even algebra years later. This mental flexibility is essential for developing confident mathematicians. In everyday life, borrowing appears constantly: calculating change at a store, figuring out how many supplies are left after using some, or even managing game points. Mastering this skill now prevents frustration and gaps in understanding that become much harder to fix in upper grades.

What your student will practice

• Regroup tens into ones when the ones digit in the minuend is smaller than the subtrahend
• Accurately subtract two-digit numbers using borrowing with correct place value notation
• Recognize when borrowing is necessary and apply the strategy consistently
• Verify answers using addition to check subtraction work

Common mistakes to watch for

The most common mistake is students forgetting to reduce the tens place by 1 after borrowing. For example, when solving 42 − 17, a student might correctly turn the 2 ones into 12, but then subtract 7 from 12 to get 5 ones—yet still use the original 4 tens instead of 3, writing 45 as the answer instead of 25. Another frequent error is borrowing even when it isn't needed; students sometimes borrow from 35 − 12 automatically, creating confusion. Watch for crossed-out numbers that show the borrowing process—if those crossed-out digits don't match the regrouped numbers written above them, your child may be losing track mid-problem.