Q: What are the factor combinations of the number 385?

 A:
Positive:   1 x 3855 x 777 x 5511 x 35
Negative: -1 x -385-5 x -77-7 x -55-11 x -35


How do I find the factor combinations of the number 385?

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 385, it is easier to work with a table - it's called factoring from the outside in.

Outside in Factoring

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.

1 385
-1 -385

Why are the negative numbers included?

When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 385.

Example:
1 x 385 = 385
and
-1 x -385 = 385
Notice both answers equal 385

With that explanation out of the way, let's continue. Next, we take the number 385 and divide it by 2:

385 ÷ 2 = 192.5

If the quotient is a whole number, then 2 and 192.5 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:

1 385
-1 -385

Now, we try dividing 385 by 3:

385 ÷ 3 = 128.3333

If the quotient is a whole number, then 3 and 128.3333 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:

1 385
-1 -385

Let's try dividing by 4:

385 ÷ 4 = 96.25

If the quotient is a whole number, then 4 and 96.25 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:

1 385
-1 385
Keep dividing by the next highest number until you cannot divide anymore.

If you did it right, you will end up with this table:

15711355577385
-1-5-7-11-35-55-77-385

More Examples

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