How to round down to nearest X number - pseudocode for VBScript

Question

Hey

I'm trying to round down a number to the nearest say 15, 20, 30. ie

726 to the nearest 30 is 700

714 to the nearest 15 is 700 etc

VBScript code would be very helpful but pseudocode would also be a huge help!

EDIT: Sorry, I forgot to say, that 726 is really a time expressed as an int, ie 07:26. So this should be 07:00, not 690

EDIT Again: I'm just extracting the minute and using the code people have answered with. Hopefully this will help someone else too. Thanks!

Thanks

Answer 1

Pseudo code:

diff = num mod nearest
return num - diff

So 726 mod 30 = 6

726 - 6 = 720

vbscript:

Function GetNearest(num, nearest)
    Dim diff = num mod nearest
    GetNearest = num - diff
End Function

Answer 2

You listed a bunch of languages in your tags. I'm going with C#, but a more generic algorithm:

int n = 726;
int q = 30;
int r = Math.Floor(n / q) * q;

Answer 3

another way to do it is just to use integer division: 726 / 30 * 30 = 720