How To Multiply Numbers #3
We've already seen how to multiply by single digit numbers using
this simple method as well as this quicker
way using regrouping. We can combine these two methods of multiplying
to multiply by 2-digit numbers as shown in the example below:
Multiplying by 2-Digit Numbers
| 586 x 23 = |
Multiply the ones (3 x 6 = 18). Write
8 in the ones' place and carry the 1 forward to the tens'
|
|
| Multiply the tens and add what was carried forward
(3 x 8 = 24 + 1 = 25). Write 5 in the tens' place and carry the
2 forward to the hundreds' |
|
| Multiply the hundreds and add what was carried forward
(3 x 5 = 15 + 2 = 17). Write 7 in the tens' place and the
1 forward in the thousands' |
|
| Add a zero* and multiply the ones (2 x 6 = 12).
Write 2 in the tens' place and carry the 1 forward to the hundreds' |
|
| Multiply the tens and add what was carried forward
(2 x 8 = 16 + 1 =17). Write 7 in the hundreds' place and carry
the 1 forward to the thousands' |
5 8 6
x 2 3 |
1
72518
1712 0 |
|
| Multiply the hundreds' and add what was carried
forward (2 x 5 = 10 + 1 =11). Write 1 in the thousands place and
1 in the ten thousands' |
5 8 6
x 2 3 |
1
72518
1 11712 0 |
|
| Add the two products to get the answer. |
5 8 6
x 2 3 |
1
72518
1 11712 0 |
1 3 4 7 8 |
|
| 586 x 23 = 13478 |
| * We really wanted to multiply by 20,
not 2. Adding a zero and multiplying by 2 is the same as multiplying
by 20. |
Try the worksheets below for more practice with multiplying by 2-digit
numbers.
You'll find more printable multiplication
worksheets here.