What is Regrouping?
Sometimes when we subtract, the top number is smaller than the bottom number in one place.
When this happens, we need to "regroup" or "borrow" from the next column to the left. It's like when you need to exchange a $10 bill for ten $1 coins!
How to Subtract with Regrouping
1️⃣ Look at the ones place. If the top number is smaller, we need to regroup.
2️⃣ Borrow 1 from the tens place (cross it out and make it 1 less).
3️⃣ Add 10 to the ones place (now you have enough to subtract!).
Let's Practice Together!
Example 1: 42 - 7
Can we subtract 7 from 2?
No! 2 is smaller than 7, so we need to regroup!
1. Cross out the 4 and make it 3 (we're borrowing 1 ten)
2. Add 10 to the ones place: 2 becomes 12
3. Now subtract: 12 - 7 = 5
4. Bring down the tens: 3
Final answer: 35
Example 2: 53 - 8
Try solving this one yourself!
1. Can we subtract 8 from 3? No! Let's regroup.
2. Change 5 tens to 4 tens, and 3 ones becomes 13 ones
3. Now subtract: 13 - 8 = 5
4. Bring down the tens: 4
Final answer: 45
Parent Tips 🌟
- Use real objects: Practice with pennies and dimes to show how regrouping works with money.
- Make it a game: Create subtraction flashcards and reward correct answers with stickers or points.
- Be patient: Regrouping can be tricky at first - celebrate small successes and keep practice sessions short and fun!