Multiplication
It helps to know your times tables! Click on the times tables picture.
Muliplying by 10
A decimal point comes after a whole number e.g. 3.4 - the number three is a whole number.
Move the decimal point one place to the right.
Example 1
2 x 10 = ?
Move the 2 from the units to the tens column.
Answer:20
Example 2
8.3 x 10= ?
Move the 8 from the units to the tens column and .3 to the units column.
Answer:83
Muliplying by 100
Move the number or numbers two places to the right.
Example 1
5 x 100 =?
Move the 5 from units to the hundreds column.
Answer:500
Muliplying by 1000
Move the decimal point three places to the right.
2.2 x 1000 = ?
Move the 2 from units to the thousands column and .2 to the hundreds column.
Answer:2,200
Muliplying Numbers
Example 1
22 x 6 = ?
- Start with the units! Mulitply
2 by 6 = 12 - Enter 2 and carry 1 to the tens
- Multiply the 2 in the tens coloumn
by 6 = 12 - Plus the 1 carried over = 13
- Enter 3 in the tens column and
carry 1 over to the hundreds column
| Th | H | T | U |
|---|---|---|---|
| 2 | 2 | ||
| 6 | |||
| 1 | 3 | 2 | |
| 1 | |||
x
Example 2
43 x 11 = ?
- Multiply 43 by 1 = 43
- Multiply 43 by 10= 430
- Add 43 + 430 = 473
| Th | H | T | U |
|---|---|---|---|
| 4 | 3 | ||
| 1 | 1 | ||
| 4 | 3 | ||
| 4 | 3 | 0 | |
| 4 | 7 | 3 | |
x
Example 3
343 x 32 = ?
- Multiply 343 by 2 = 686
- Multiply 343 by 30= 10,290
- Add 686 + 10290= 10,976
| Th | H | T | U |
|---|---|---|---|
| 3 | 4 | 3 | |
| 3 | 2 | ||
| 6 | 8 | 6 | |
| 10, | 2 | 9 | 0 |
| 10, | 9 | 7 | 6 |
x
VIDEO
Have a look at the demonstration on the video to enhance your learning.
