Vertically align numbers with Larger Number on top:
| 3 | 0 | |
| − | 1 | 8 |
Subtract using place value:
| Tens | Ones | |
|---|---|---|
| 2 | 10 | |
| 30 | 3 | 0 |
| 18 | 1 | 8 |
| Difference | 1 | 2 |
Column traversal from right to left
Ones column:
Ones column:
- Since 0 is less than 8, we have to borrow 1 from the Tens column
- As a result, 0 becomes 10, and 10 − 8 = 2
- The 3 in the Tens column becomes 2
Tens column:
- 2 − 1 = 1
| 2 | 10 | |
| 3 | 0 | |
| − | 1 | 8 |
| 1 | 2 |
Therefore, the Difference between 30 and 18 is 12
Check computation by comparing Larger Number and the Sum of Smaller Number and Difference:
| 1 | ||
| 1 | 8 | |
| 1 | 2 | |
| 3 | 0 |
Sum of Smaller Number and Difference = 30
Sum of Smaller Number and Difference = Larger Number (30 = 30) ✓
