Mastering 2-Digit Subtraction with Regrouping

When performing two-digit subtraction, sometimes we encounter situations where we need to regroup or borrow a number from another digit to complete the subtraction. This lesson will guide you through the steps of two-digit subtraction with regrouping, ensuring clarity and understanding.

Understanding the Basics

Two-digit numbers consist of a tens place and a ones place. Consider the example of subtracting 34 from 58:

58

• 34

  ---

We start from the rightmost column (the ones place).

Step-by-Step Example: 58 - 34

1. Look at the Ones Place: 8 (from 58) - 4 (from 34)
   Since 8 is greater than 4, we can subtract directly:
   8 - 4 = 4
   So we write down 4 in the ones place of the answer.

2. Look at the Tens Place: 5 (from 58) - 3 (from 34)
   Since 5 is greater than 3, we can also subtract directly:
   5 - 3 = 2
   Add that to the answer.

Now, combining both results, we have:

58

• 34

  ---

  24

Example Requiring Regrouping: 53 - 29

Now let's consider a more challenging example where regrouping is necessary:

53

• 29

  ---

1. Look at the Ones Place: 3 (from 53) - 9 (from 29)
   Here, 3 is less than 9, so we need to regroup. This involves borrowing from the tens place.

2. Regrouping:
   We take 1 ten (which is worth 10) from the 5 in the tens place of 53.
   Now we have:

   • The tens place becomes 4 (5 - 1)
   • The ones place becomes 13 (3 + 10 from regrouping)

So now we are subtracting:

43

• 29

  ---

3. Subtract the Ones Place: 13 - 9 = 4
   Write 4 in the ones place of the answer.

4. Subtract the Tens Place: 4 - 2 = 2
   Write 2 in the tens place.

Combine the results:

53

• 29

  ---

  24

Final Answer

The result of 53 - 29 is 24.

Useful Tips for 2-Digit Subtraction with Regrouping

• Practice Regularly: The more you practice, the more comfortable you will become with regrouping.
• Write Each Step Clearly: When you are subtracting, keep your work organized and write each step down to avoid confusion.
• Double-Check Your Work: Always go back and double-check your math, especially when you have regrouping involved.
• Use Visual Aids: Using objects like counters can help visualize the borrowing process.
• Stay Calm: Regrouping can be tricky at first, but with patience, it will become easier.

By following these steps and practicing, you will become proficient in two-digit subtraction with regrouping!