Lesson 8: Two-Digit Subtraction (32 - 18)
Intermediate Level
Instructions
- Let's subtract 18 from 32 across two columns.
- Set 32: In the tens column, slide 3 blue beads up (30); in the ones column, slide 2 blue beads up (2).
- Subtract 18: In the tens column, slide 1 blue bead down (20); in the ones column, borrow 1 ten (10 + 2 = 12), then slide 8 blue beads down (clear 2, borrow 10, subtract 8).
- The value should be 14!
T
100B
10B
B
100M
10M
M
100K
10K
K
100
10
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
5
1
1
1
1
Value: 0