1.18⋅15
Multiply 5 by 8. Place the ones digit (0) in the result line and carry the tens digit (4). There is one result line for each digit in 15.
| 4 | |||
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 0 |
Multiply 5 by 1 and add the carried 4. Place the result in the next column in the result line. There is one result line for each digit in 15.
| 4 | |||
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 9 | 0 |
Multiply 5 by 1. Place the result in the next column in the result line. There is one result line for each digit in 15.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 |
Multiply 1 by 8. Place the result in the next column in the result line. There is one result line for each digit in 15.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 8 |
Multiply 1 by 1. Place the result in the next column in the result line. There is one result line for each digit in 15.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 8 |
Multiply 1 by 1. Place the result in the next column in the result line. There is one result line for each digit in 15.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 |
Add the numbers in each column. In this case, add 0+0, then place the 0 in the result line.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 | |
| 0 |
Add the numbers in each column. In this case, add 9+8, then place the 7 in the result line and carry the 1.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 | |
| 7 | 0 |
Add the numbers in each column. In this case, add 5+1+1, then place the 7 in the result line.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 | |
| 7 | 7 | 0 |
Add the numbers in each column. In this case, add 0+1, then place the 1 in the result line.
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 | |
| 1 | 7 | 7 | 0 |
| 1 | .1 | 8 | |
| ⨯ | 1 | 5 | |
| 5 | 9 | 0 | |
| 1 | 1 | 8 | |
| 1 | 7 | 7 | 0 |
To find the number of decimal places needed in the answer, add the number of decimal places in the multiplier and multiplicand. In this case, there is a total of 2, so the answer must have 2 decimal places as well.
17.7
Multiply 1.18*15