What sums equal 80?

Answer 1

There are infinitely many.

Involving integers (whole numbers) there are:

0 + 80, 1 + 79, 2 + 78, .... 78 + 2, 79 + 1, 80 + 0, 81 + -1, 82 + -2, .....

When you include non-integers there are:

½ + 79½, 1½ + 78½, ...

1.1 + 78.9, 1.2 + 78.8, ....

3.1 + 76.9, 3.14 + 76.86, 3.141 + 76.859, 3.1415 + 76.8585, 3.14159 + 76.85841, ...., π + (80 - π)

Answer 2

There are infinitely many possible answer. One such is 37.538 + 42.462