How to Teach Subtraction with Regrouping (Borrowing)

Subtraction with regrouping is one of the first times math asks a child to do something that feels like a trick. Your child looks at 52 minus 27, sees that 2 is smaller than 7, and gets stuck. Many kids simply flip the numbers and subtract 2 from 7. The good news is that regrouping is not a trick at all. Once a child sees what is really happening, the steps make sense and stop feeling like magic.

You may have learned this as borrowing. Schools now usually call it regrouping or trading, because nothing is ever given back. A ten is broken into ten ones. That is the whole idea.

Start with what the numbers mean

Before any steps on paper, make sure your child knows that 52 means 5 tens and 2 ones. If that idea is shaky, regrouping will be shaky too. Ask quick questions: How many tens are in 52? How many ones? What number is 3 tens and 8 ones? If your child answers these easily, you are ready. If not, spend a few days on place value first. It will save you weeks later.

Use something your child can touch

You do not need special materials. Bundles of 10 straws held with a rubber band work well, and so do dimes and pennies. Build 52 as 5 bundles and 2 loose straws. Now ask your child to take away 27, which means 2 bundles and 7 loose straws.

Your child will quickly notice there are only 2 loose straws, so they cannot take away 7. Ask: what could we do? Most kids figure out on their own that they can pull the rubber band off one bundle. Now there are 4 bundles and 12 loose straws. The amount has not changed; it is still 52. It is just arranged differently. Now they can take away 7 loose straws and 2 bundles, leaving 2 bundles and 5 loose straws: 25.

Do this with objects three or four times before moving to paper. The physical memory of breaking a bundle is what makes the written steps stick.

The written steps

1. Line up the numbers by place: ones under ones, tens under tens.
2. Start with the ones column. Ask: is the top digit big enough to take the bottom digit away?
3. If not, go to the tens column. Cross out the tens digit and write one less above it.
4. Put a small 1 in front of the ones digit, making it 10 more. So 2 becomes 12.
5. Subtract the ones: 12 minus 7 is 5.
6. Subtract the tens: 4 minus 2 is 2. The answer is 25.
7. Check by adding: 25 plus 27 should equal 52.

Say the steps out loud while you write them together, using real words: I am trading one ten for ten ones. Language like that connects the paper back to the straws.

Common mistakes and how to fix them

• Subtracting the smaller digit from the bigger one no matter which is on top. For 52 minus 27, the child writes 35. Fix: always ask, which number are we starting with? Go back to the straws if needed.
• Regrouping when it is not needed. Some children get so used to crossing out that they do it every time. Fix: before each problem, have them look at the ones column and say yes or no to trading.
• Forgetting to reduce the tens digit. The child makes 12 ones but still subtracts from 5 tens. Fix: cross out first, then write the new number, every single time.
• Trouble with zeros, like 300 minus 128. Here the child must trade a hundred for ten tens, then a ten for ten ones. Fix: model it with hundreds, tens, and ones, and go slowly. This is a separate skill that deserves its own practice.

If your child is frustrated, drop back to one easier level for a day. Two-digit problems without regrouping, done quickly and correctly, rebuild confidence faster than more hard problems.

A 10-minute activity: the trading game

Grab dimes and pennies, or straws and rubber bands. Each player starts with 50 cents written as 5 dimes. Take turns rolling two dice and adding them up; that is how many cents you must pay the bank. When you do not have enough pennies, you must trade a dime for 10 pennies before paying. The first player to reach zero wins. Kids get dozens of regrouping moments without a single worksheet, and they say the steps out loud naturally.

After a few rounds, write down one of the moves as a subtraction problem. Show your child that what they just did with coins is exactly what the written method records.

How much practice is enough?

Short and frequent beats long and rare. Five to eight problems a day, with each one checked right away, is usually more useful than a page of thirty done alone. Mix in a few problems that do not need regrouping so your child has to decide each time. When your child can do a mixed set accurately and explain why they traded, move on to three-digit numbers and then to problems with zeros.

When practice needs to be more targeted

Every child gets stuck in a slightly different spot. One forgets to cross out, another struggles only with zeros, another still is not sure about tens and ones. Study Tutor's AI tutor looks at the exact kind of mistake your child makes and builds printable practice for that specific difficulty, so the next page fits where they are right now.