Subtraction of Two-Digit Numbers with Regrouping

An example of subtraction with two digit numbers and regrouping is 56 – 38. We will give and explain three different methods for this and, as always, you can choose to use whichever method is most comfortable for you.

Method 1: This method has three steps.
Reminder: The number that is subtracted FROM is the MINUEND. The number that is being subtracted is the SUBTRAHEND. The result is known as the DIFFERENCE.
1. Split the subtrahend into the tens and ones digits.
38 = 3 tens + 8 ones
38 = 30 + 8
2. First, subtract the tens digit from the minuend.
56 – 30 = 26
3. From that result, subtract the ones digit.
26 – 8 = 18
So, 56 – 38 = 18

Try these practice problems using method 1.
Practice 1:
42 - 27
Split the subtrahend: 27 = 20 + (7)
Subtract tens from the minuend: 42 – 20 = (22)
Subtract the ones digit: 22 – (7) = (15)

Practice 2:
56 – 39
39 = (30) + 9
56 – (30) = (26)
(26) – 9 = (17)

Practice 3:
72 – 24
24 = (20) + (4)
72 – (20) = (52)
(52) – (4) = (48)

Solve Mentally:
1. 35 – 16
2. 48 – 39
3. 51 – 24
4. 72 – 66
5. 53 – 47
6. 37 – 18

Method 2: This method has three steps. We will use the example 75 – 28.
1.  Round the subtrahend to the nearest ten, or round number.
28 à 30
2. Subtract the rounded number from the minuend.
75 – 30 = 45
3. Adjust. If, when rounding, you added an amount, add that amount to the answer and vice versa.
Caution: This is the opposite for addition.
45 + 2 = 47

Solve these problems using method 2.
Practice 1:
44 – 15
Round the subtrahend: 15 à(20)
Subtract round number from the minuend: 44 – (20) = (24)
Adjust accordingly: 24 + (5) = (29)

Practice 2:
52 – 33
33 à(30)
52 – (30) = (22)
(22) – 3 = (19)

Practice 3:
31 - 14
14 à(10)
31 – (10) = (21)
(21) – (4) = (17)

Solve Mentally:
1. 35 – 16
2. 58 – 39
3. 51 – 24
4. 72 – 46
5. 53 – 47
6. 36 – 17