Vertically align numbers with Larger Number on top:
| 8 | . | 2 | 0 | 0 | |
| − | 1 | . | 3 | 8 | 5 |
Subtract using place value:
| Ones | Tenths | Hundredths | Thousandths | ||
|---|---|---|---|---|---|
| 11 | 9 | ||||
| 7 | 1 | 10 | 10 | ||
| 8.2 | 8 | . | 2 | 0 | 0 |
| 1.385 | 1 | . | 3 | 8 | 5 |
| Difference | 6 | . | 8 | 1 | 5 |
Column traversal from right to left
Thousandths column:
Thousandths column:
- Since 0 is less than 5, we have to borrow 1 from the Hundredths column
- As a result, 0 becomes 10, and 10 − 5 = 5
- The 0 in the Hundredths column becomes 9 after borrowing 1 from its regrouped value of 10
Hundredths column:
- 9 − 8 = 1
- Because it was the first nonzero digit to the left of the 0 in the Thousandths column, the 2 in the Tenths column became 1 after 1 was borrowed for the purpose of regrouping the 0 in the Hundredths column (borrowing across a 0)
Tenths column:
- Since 1 is less than 3, we have to borrow 1 from the Ones column
- As a result, 1 becomes 11, and 11 − 3 = 8
- The 8 in the Ones column becomes 7
Ones column:
- 7 − 1 = 6
| 11 | 9 | ||||
| 7 | 1 | 10 | 10 | ||
| 8 | . | 2 | 0 | 0 | |
| − | 1 | . | 3 | 8 | 5 |
| 6 | . | 8 | 1 | 5 |
Therefore, the Difference between 8.2 and 1.385 is 6.815
Check computation by comparing Larger Number and the Sum of Difference and Smaller Number:
| 1 | 1 | 1 | |||
| 6 | . | 8 | 1 | 5 | |
| 1 | . | 3 | 8 | 5 | |
| 8 | . | 2 | 0 | 0 |
Sum of Difference and Smaller Number = 8.2 (trailing zeros are dropped)
Sum of Difference and Smaller Number = Larger Number (8.2 = 8.2) ✓
