When subtracting two-digit numbers, sometimes the digit in the top number (minuend) is smaller than the digit in the bottom number (subtrahend). In such cases, we need to regroup (borrow) from the next higher place value.

 Example: Subtract 27 from 43

    Write the numbers one below the other:

                                           43
                                          _27
                                        ______`

2. Subtract the ones place:
– The ones place of 43 is 3.
– The ones place of 27 is 7.
– Since 3 is smaller than 7, we need to borrow 1 ten from the tens place of 43.

3. Regroup (borrow):
– Take 1 ten from the tens place of 43, leaving 3 tens (or 30).
– Add the borrowed ten to the ones place: 3 becomes 13.

Now, we have:
“`
3(4 becomes 3) 13 (3 becomes 13)
– 2 7
“`

4. Subtract the ones place again:
– Subtract 7 from 13:
“`
13 – 7 = 6
“`

5. Write the result of the ones place subtraction below the line in the ones place:
                                            3  13
                                          _2     7
                                          ________

6. Subtract the tens place:
– The tens place of 43 (after borrowing) is 3.
– The tens place of 27 is 2.
– Subtract 2 from 3:
“`
3 – 2 = 1
“`

7. Write the result of the tens place subtraction below the line in the tens place:

3 13
– 2 7
—-
16
“`

 So, 43 – 27 = 16.

Steps Recap:
1. Write the numbers with one below the other, aligning the digits by place value.
2. If the digit in the ones place of the minuend is smaller than the subtrahend, regroup (borrow) from the tens place.
3. Subtract the digits in the ones place.
4. Subtract the digits in the tens place.
5. Write down the final answer.