Q: What are the factor combinations of the number 13?
A:
Positive:
1 x 13
Negative:
-1 x -13
A:
Positive:
1 x 13
Negative:
-1 x -13
Unfortunately, there's not simple formula to identifying all of the factors of a number and it can be a tedious process when trying to identify the divisors of larger numbers. To find the factor combinations of the number 13, it is easier to work with a table - it's called factoring from the outside in.
We start by creating a table and writing 1 on the left side and then the number we're trying to find the factors for on the right side in a table. Then, below that, write the numbers as a negative as well.
| 1 | 13 | |
| -1 | -13 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 13.
Example:
1 x 13 = 13
and
-1 x -13 = 13
Notice both answers equal 13
With that explanation out of the way, let's continue. Next, we take the number 13 and divide it by 2:
13 ÷ 2 = 6.5
If the quotient is a whole number, then 2 and 6.5 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 13 | |
| -1 | -13 |
Now, we try dividing 13 by 3:
13 ÷ 3 = 4.3333
If the quotient is a whole number, then 3 and 4.3333 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 13 | |
| -1 | -13 |
Let's try dividing by 4:
13 ÷ 4 = 3.25
If the quotient is a whole number, then 4 and 3.25 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 13 | |
| -1 | 13 |
If you did it right, you will end up with this table:
| 1 | 13 |
| -1 | -13 |
Here are some more numbers to try:
Try the factor calculator