Column Subtraction with Exchanging!

Year 3: Subtracting 2-Digit Numbers (With Regrouping)

Time to Exchange!

Let's subtract using columns. If the top ones digit is smaller than the bottom ones digit, you'll need to exchange one ten from the tens column. This makes the ones digit bigger by 10, and the tens digit smaller by 1 (you can show this above the numbers). Then subtract the ones, and then the tens!

Practice Column Subtraction with Regrouping

Write your answers in the boxes. Remember to exchange if you need to!

Subtraction Power-Up: Time for Regrouping (Borrowing!)

Hello Maths Superstars! You've been practising column subtraction like a pro. Now, get ready for an exciting new skill: regrouping (sometimes called "exchanging" or "borrowing") when you subtract two 2-digit numbers! This is what we do when the ones digit on top is smaller than the ones digit we need to take away. It’s like asking the tens place for a little help!

What is "Regrouping" or "Borrowing" in Subtraction?

Sometimes, when we try to subtract the ones column, we find we don't have enough ones in the top number. For example, if we have 2 ones and need to take away 5 ones, we can't do it easily! So, we "borrow" or "exchange" 1 ten from the tens column of the top number. That 1 ten becomes 10 ones, which we add to our original ones, giving us enough to subtract!

Let's Subtract with Regrouping: Example 52 − 27

Here’s how it works, step-by-step:

Step 1: Set up your column subtraction. Write the numbers one above the other, with the bigger number on top. Line up the tens and ones.

   T O  (T for Tens, O for Ones)
   5 2
−  2 7
------  (Draw a line for your answer)

Step 2: Look at the Ones Column – Do we need to regroup? In the 'Ones' (O) column, we have 2 take away 7 (2 − 7). Uh oh! We can't take 7 away from 2 easily. So, yes, we need to regroup!

Step 3: Regroup (Borrow) from the Tens Column.

Go to the 'Tens' (T) column of the top number (52). It has 5 tens.
We "borrow" 1 ten from these 5 tens. So, the 5 tens becomes 4 tens. Cross out the 5 and write a small 4 above it.
The 1 ten we borrowed is worth 10 ones. We add these 10 ones to the 2 ones we already had in the ones column. So, 2 + 10 = 12 ones. Cross out the 2 in the ones column and write a small 12 above it.

     ⁴   ¹²   <-- Shows the regrouping
   T   O
   5   2
−  2   7
-------

Step 4: Now Subtract the Ones Column. Look at our new 'Ones' (O) column. We now have 12 take away 7 (12 − 7). 12 − 7 = 5. Write the 5 under the ones column.

     ⁴   ¹²
   T   O
   5   2
−  2   7
-------
       5

Step 5: Subtract the Tens Column. Now look at our new 'Tens' (T) column. Remember we used one ten, so we have 4 tens take away 2 tens (4 − 2). 4 − 2 = 2. Write the 2 under the tens column.

     ⁴   ¹²
   T   O
   5   2
−  2   7
-------
   2   5

So, 52 − 27 = 25! You've successfully used regrouping!

Practice Your Regrouping Skills! (18 Questions)

Ready to become a regrouping master? Here are 18 column subtraction questions where you'll need to subtract two 2-digit numbers and use regrouping (borrowing) from the tens to the ones. Remember the steps: check the ones, regroup if you need to, then subtract the ones, then subtract the tens!

(Your web app with the 18 questions will go here. The app should ideally visually support the regrouping process or allow space for it.)

Why is Learning to Regroup (Borrow) So Important?

Solves Most Subtraction Problems: You need regrouping for many subtraction sums you'll encounter.
Deepens Place Value Understanding: It shows you really understand that 1 ten is the same as 10 ones.
Boosts Accuracy: Following the regrouping steps correctly helps you get the right answers.
Builds Big Maths Confidence: Mastering regrouping is a major step in becoming a confident mathematician!

Tips for Grown-Ups: Explaining Regrouping (Exchanging/Borrowing)

Regrouping in subtraction (often called "borrowing" or "exchanging") is when a digit in a higher place value column is exchanged for 10 units of the next column to its right to allow subtraction to occur. For 2-digit numbers, this means exchanging 1 ten for 10 ones.

Use Base-Ten Blocks: This is the BEST way to introduce regrouping. Physically show how one 'ten rod' is exchanged for ten 'one cubes'. Let children do the exchange themselves.
Clear Notation: Teach a consistent way to show the regrouping on paper: crossing out the original tens digit and writing the new, smaller tens digit above; crossing out the original ones digit and writing the new, larger ones digit (original ones + 10) above.
Language Matters: While "borrowing" is common, "exchanging" or "regrouping" can be more accurate as you're not giving the ten back. Use the term your child's school uses if possible, but ensure they understand the concept of the exchange.
Step-by-Step Practice: Go through each step slowly and clearly many times. Check the ones first: "Can we do 2 take away 7? No? So we need to regroup!"