Regrouping Tens and Ones II

Learn how to exchange tens and ones like a math magician!

What is Regrouping?

Regrouping is like trading blocks when you don't have enough!
Sometimes when we're adding or subtracting, we need to exchange 10 ones for 1 ten, or break 1 ten into 10 ones. It's like trading 10 pennies for 1 dime!

How to Regroup

1️⃣ Count your ones. If you have 10 or more, group them into a ten!

2️⃣ If you don't have enough ones to subtract, break a ten into 10 ones

3️⃣ Always remember: 1 ten = 10 ones (they're equal!)

Let's Practice Together!

Example 1: Addition with Regrouping

Solve: 27 + 15

2 tens

+ 7 ones

+

1 ten

+ 5 ones

1. Add the ones: 7 + 5 = 12 ones

2. Regroup 10 ones into 1 ten: Now you have 1 ten and 2 ones left

3. Add the tens: 2 + 1 + 1 (regrouped) = 4 tens

4. Final answer: 4 tens and 2 ones = 42

Example 2: Subtraction with Regrouping

Solve: 32 - 15

3 tens

+ 2 ones

-

1 ten

+ 5 ones

1. We need to subtract 5 ones, but only have 2 ones

2. Regroup 1 ten into 10 ones: Now we have 2 tens and 12 ones

3. Subtract the ones: 12 - 5 = 7 ones

4. Subtract the tens: 2 - 1 = 1 ten

5. Final answer: 1 ten and 7 ones = 17

Parent Tips 🌟

  • Use real objects: Practice with coins (pennies and dimes) or cereal pieces to make regrouping tangible
  • Highlight the "why": Explain that regrouping helps us when we don't have enough of one type (like needing more ones to subtract)
  • Make it a game: Create a "trading post" where your child can exchange 10 ones for 1 ten and vice versa

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