How many divisions?

[x-ice]

How can i establish how many times i need to divide a number by 2 before it gets to 0 without actually doing the divisions (these will be done later)?

I want to do this because i need to establish how many array spaces i need for all the divided numbers to go into.

For Example. If the number was 96, i would need to divide this 7 times before it goes to zero.

96
48
24
12
6
3
1.5
0

[Rassis]

Let X be your number to be divided by 2 and n the number of times X can be divided by 2 before the result becomes less than 1. Then, X/2^n < 1. From this expression you derive n = log(X)/log(2) and approximate the result to the nearest upper integer. For instance:
X = 96; n = 7
X = 300; n = 9
X = 5000; n = 13

Hope this helps.

[x-ice]

Let X be your number to be divided by 2 and n the number of times X can be divided by 2 before the result becomes less than 1. Then, X/2^n < 1. From this expression you derive n = log(X)/log(2) and approximate the result to the nearest upper integer. For instance:
X = 96; n = 7
X = 300; n = 9
X = 5000; n = 13

Hope this helps.

Ok i have a slight problem, the result in getting rounded down to the nearest integer in most cases (i guess it because it is below n.5). How can i prevent this from happening? Here is my code.

Private Function Dec2Bin(ByVal DecNum As Int32) As Int32
        Dim DivNum As Int32
        'Establish how many divisions will be done
        DivNum = CInt(Log(DecNum) / (Log(2))[b] + 1[/b])
        'TEST
        MessageBox.Show(CStr(DivNum))
    End Function

p.s. I have tried to add the code in bold, this solves the problem for the numbers that produce incorrect results (e.g 300 and 5000) but for the numbers that produce correct results (e.g. 96) it makes the result incorrect.

[Rassis]

I said that the result should be rounded up to the nearest integer and not rounded down. Thus you allways get the right number.