Vertically align numbers with Larger Number on top:
| 7 | 9 | 0 | 5 | |
| − | 4 | 7 | 9 | 9 |
Subtract using place value:
| Thousands | Hundreds | Tens | Ones | |
|---|---|---|---|---|
| 9 | ||||
| 8 | 10 | 15 | ||
| 7,905 | 7 | 9 | 0 | 5 |
| 4,799 | 4 | 7 | 9 | 9 |
| Difference | 3 | 1 | 0 | 6 |
Column traversal from right to left
Ones column:
Ones column:
- Since 5 is less than 9, we have to borrow 1 from the Tens column
- As a result, 5 becomes 15, and 15 − 9 = 6
- The 0 in the Tens column becomes 9 after borrowing 1 from its regrouped value of 10
Tens column:
- 9 − 9 = 0
- Because it was the first nonzero digit to the left of the 5 in the Ones column, the 9 in the Hundreds column became 8 after 1 was borrowed for the purpose of regrouping the 0 in the Tens column (borrowing across a 0)
Hundreds column:
- 8 − 7 = 1
Thousands column:
- 7 − 4 = 3
| 9 | ||||
| 8 | 10 | 15 | ||
| 7 | 9 | 0 | 5 | |
| − | 4 | 7 | 9 | 9 |
| 3 | 1 | 0 | 6 |
Therefore, the Difference between 7,905 and 4,799 is 3,106
Check computation by comparing Larger Number and the Sum of Smaller Number and Difference:
| 1 | 1 | |||
| 4 | 7 | 9 | 9 | |
| 3 | 1 | 0 | 6 | |
| 7 | 9 | 0 | 5 |
Sum of Smaller Number and Difference = 7,905
Sum of Smaller Number and Difference = Larger Number (7,905 = 7,905) ✓
