What two numbers add up to 15?

Sometimes you come across numbers that appear to be enormous. Knowing how to divide a large number into two smaller numbers (a number pair) can help you solve sums in your head.

Most numbers have multiple number pairs.

The number 15 is composite. 15 = 1 x 15 or 3 x 5. 15-factors: 1, 3, 5, 15. 15 = 3 x 5 prime factorization An infinite number of possible combinations of two numbers add up to 15. https://mycalcu.com/ Here are some negative number examples:

-1 + 16 = 15

-2 + 17 = 15

-3 + 18 = 15

Here are some more examples involving two decimal numbers that add up to 15:

1.25 + 13.75 = 15

2.50 + 12.5 = 15

3.75 + 11.25 = 15

As the preceding lists demonstrate, it is possible to go on indefinitely. When answering the question "What two numbers add up to 15?" it may be more interesting to set some criteria to limit the outcome. We will establish the following criteria:

1) Only positive whole numbers can add up to 15.

2) Because a+b=29 is the same as b+a=29, we only need to list it once.