Subtracting Within 100 With Regrouping: Worksheet 1
Every problem on this page needs a ten broken into ones: subtracting within 100 with regrouping, forty column problems for ages 7-9 who can already subtract without borrowing.
2 A4 pages · for home and classroom use
Labugen
Subtraction up to 100 with regrouping
set no. 7303
- 32-27
- 73-7
- 21-19
- 97-48
- 31-8
- 80-42
- 96-78
- 20-6
- 20-8
- 34-15
- 100-1
- 81-37
- 74-39
- 48-39
- 30-14
- 13-8
- 62-25
- 21-18
- 92-8
- 81-46
- 85-7
- 90-71
- 23-17
- 43-35
- 54-39
- 98-49
- 42-13
- 81-24
- 42-37
- 45-36
- 22-5
- 60-27
- 71-19
- 83-64
- 80-16
- 41-33
- 45-7
- 11-7
- 32-26
- 90-51
How to use this worksheet
- Model problem 1, 32 − 27: 2 ones are not enough for 7, so cross out the 3, write 2, and make the 2 ones into 12; 12 − 7 = 5, 2 − 2 = 0, answer 5.
- Watch the eight top numbers that end in zero, such as 80 − 42 and 60 − 27.
- Check each row of five with the answer key and redo mistakes the next day.
What this worksheet teaches
In all forty problems the top ones digit is smaller than the bottom one, so borrowing is needed every time. Twenty-nine problems subtract a two-digit number (97 − 48, 81 − 37, 71 − 19), and eleven subtract a one-digit number (73 − 7, 92 − 8, 11 − 7). Answers range from 2 to 99. Forty repetitions make the steps automatic.
Borrowing, step by step
Borrowing means trading one ten for ten ones; the value of the number does not change. In 80 − 42 there are no ones at all: one of the 8 tens becomes 10 ones, 10 − 2 = 8 and 7 − 4 = 3, giving 38. The first problem in the third row, 100 − 1, needs borrowing across two zeros; counting back one step to 99 is a quick check. Adding the answer to the bottom number should always give the top number: 38 + 42 = 80.