Vertically align numbers with Larger Number on top:
| 1 | 0 | 0 | |
| − | 4 | 5 |
Subtract using place value:
| Hundreds | Tens | Ones | |
|---|---|---|---|
| 9 | |||
| 0 | 10 | 10 | |
| 100 | 1 | 0 | 0 |
| 45 | 4 | 5 | |
| Difference | 5 | 5 |
Column traversal from right to left
Ones column:
Ones column:
- Since 0 is less than 5, we have to borrow 1 from the Tens column
- As a result, 0 becomes 10, and 10 − 5 = 5
- The 0 in the Tens column becomes 9 after borrowing 1 from its regrouped value of 10
Tens column:
- 9 − 4 = 5
- Because it was the first nonzero digit to the left of the 0 in the Ones column, the 1 in the Hundreds column became 0 after 1 was borrowed for the purpose of regrouping the 0 in the Tens column (borrowing across a 0)
Hundreds column:
- 0 − 0 = 0
Note: Leading zero is dropped
| 9 | |||
| 0 | 10 | 10 | |
| 1 | 0 | 0 | |
| − | 4 | 5 | |
| 5 | 5 |
Therefore, the Difference between 100 and 45 is 55
Check computation by comparing Larger Number and the Sum of Difference and Smaller Number:
| 1 | 1 | ||
| 5 | 5 | ||
| 4 | 5 | ||
| 1 | 0 | 0 |
Sum of Difference and Smaller Number = 100
Sum of Difference and Smaller Number = Larger Number (100 = 100) ✓
