How many ways can you get to 45 in math?

Answer 1

Infinitely many.

Start with the sum of two integers:

22 + 23, 21 + 24, ... , 1 + 44, 0 + 45, -1 + 46, -2 + 47 and so on, for ever.

Then consider numbers to 1 decimal place:

22.5 + 22.5, 22.4 + 22.6, 22.3 + 22.7 and so on. Again, for ever.

Then consider numbers to 2 decimal places, and then 3 dp, 4 dp and so on and on - for ever! And at each stage you have an infinite number of pairs.

Next, consider sums of three of numbers, and then four numbers, five, and so on.

And you have not even started on multiplications, or powers or logarithms or inverses of the basic trigonometric ratios or the reciprocal ratios. And that is just the start!