Hitting every number

Common problem I'm having with a few patches, so I thought I'd ask!

Let's say I'm measuring a series of numbers, like 0-1500. And I have an 'if' testing for all numbers above 750.

And that I'm scrolling through all the numbers using a slider, and the mouse to control the slider.

Now if I drag the mouse across the slider fast from right to left, I would assume that my if statement would reveal the last numbers above 750, which would be 751.

But this is not always the case.

If I drag it fast, I get varying results, if I drag it slow, I get different results again, but closer to 751. (generally, not 751 however).

Is there a way to make sure the slider outputs every number on the way back down to zero?