2 Digit Addition with Regrouping – Carrying and Place Value for Kids

Understanding Regrouping in Two-Digit Addition

Introduction to Place Value

When we add two-digit numbers, it’s important to know about **place value**. Place value tells us how much a number is worth based on where it is. In two-digit numbers, we look at two places: the **tens place** and the **ones place**.

Breaking Down Two-Digit Numbers

Let’s look at the number **32**. The **3** is in the tens place, which means it stands for **30** (or three groups of ten). The **2** is in the ones place, which means it stands for **2** (or two single blocks).

Simple Addition Example

Let’s add **32** and **11**. The number **11** has **1** single block and **1** group of ten.

1. **Count the ones**:

• From 32 (2 ones) and 11 (1 one), we have:
• 2 + 1 = 3.
• We write **3** in the ones place.

2. **Count the tens**:

• From 32 (3 tens) and 11 (1 ten), we have:
• 3 + 1 = 4.
• We write **4** in the tens place.

So, **32 + 11 = 43**.

Adding with Regrouping

Now, let’s see what happens when we add **32** and **29**. The number **29** has **9** single blocks and **2** groups of ten.

1. **Count the ones**:

• From 32 (2 ones) and 29 (9 ones), we have:
• 2 + 9 = 11.
• We can’t write **11** in the ones place because it’s too big!

2. **Regrouping**:

• We change **10** ones into a group of ten. This leaves us with **1** in the ones place.
• We move the **1** group of ten to the tens place.

3. **Count the tens**:

• Now we have:
• 3 (from 32) + 2 (from 29) + 1 (carried over) = 6.
• We write **6** in the tens place.

So, **32 + 29 = 61**.

Real-World Application: Cookies

Let’s use this idea with cookies! Imagine you have **29 cookies** (2 boxes of 10 cookies and 9 single cookies) and you want to add **17 more cookies** (1 box of 10 cookies and 7 single cookies).

1. **Count the ones**:

• From 29 (9 single cookies) and 17 (7 single cookies), we have:
• 9 + 7 = 16.
• We put **10** cookies into a box, leaving us with **6** single cookies.

2. **Regrouping**:

• We move the full box of cookies (10) to the tens place.

3. **Count the tens**:

• Now we have:
• 2 (from 29) + 1 (from 17) + 1 (carried over) = 4.
• We write **4** in the tens place.

So, **29 + 17 = 46**.

Conclusion

Now you know how to add two-digit numbers and use regrouping! Try practicing with more numbers to get even better at it!