Title: Subtraction with Regrouping

Introduction: Hello students! Today, we will be learning about subtraction with regrouping. This method is used when we need to subtract larger numbers and the digit in the top number is smaller than the digit in the bottom number. By the end of this lesson, you will be able to confidently solve subtraction problems with regrouping.

I. Understanding Place Value: Before we dive into subtraction with regrouping, let’s review place value. In a number, each digit has a specific place value. The place values are ones, tens, hundreds, thousands, and so on. For example, in the number 345, the digit 5 is in the ones place, 4 is in the tens place, and 3 is in the hundreds place.

II. Subtraction without Regrouping: Let’s start with a simple subtraction problem without regrouping. Consider the problem: 52 - 18. To solve this, we subtract the ones place first, which gives us 2 - 8. Since 2 is smaller than 8, we cannot subtract directly. Therefore, we borrow 1 from the tens place, making it 4. Now, we have 12 - 8, which equals 4. Finally, we subtract the tens place, which gives us 4 - 1, resulting in 3. Therefore, 52 - 18 = 34.

III. Subtraction with Regrouping: Now, let’s move on to subtraction problems that require regrouping. Consider the problem: 345 - 187. Start by subtracting the ones place, which gives us 5 - 7. Since 5 is smaller than 7, we need to borrow from the tens place. We regroup the 4 in the tens place as 3 tens and 10 ones. Now, we have 15 - 7, which equals 8. Next, we subtract the tens place, which gives us 3 - 8. Again, we need to borrow from the hundreds place. We regroup the 3 in the hundreds place as 2 hundreds and 10 tens. Now, we have 13 - 8, which equals 5. Finally, we subtract the hundreds place, which gives us 2 - 1, resulting in 1. Therefore, 345 - 187 = 158.

IV. Practice Problems: Now, let’s practice some subtraction problems with regrouping together. Solve the following problems:

1. 724 - 398
2. 956 - 487
3. 1,234 - 567

Take your time to solve each problem, and remember to regroup when necessary.

Conclusion: Great job, everyone! Today, we learned about subtraction with regrouping. Remember to always start from the rightmost digit and borrow when necessary. With practice, you will become more comfortable with this method. Keep practicing and soon you’ll be a subtraction with regrouping expert!