Logarithm is different using VBA and Excel function

Question

I\'m trying to get the log of a number but it looks like the Worksheet function gives one answer, and VBA another.

In VB, using Log(Range(\"A2\")) where

Answer 1

Function roundit1(nn As Variant, sd As Variant)
    nn = Val(nn)
    If Not (nn = 0) Then
        xx = (1 + Int(Log(Abs(nn)) / Log(10)))
    Else
        xx = 0
    End If
    ' significant digits
    roundit = sd - xx
    If roundit < 0 Then roundit = 0
   roundit1 = Round(nn, roundit)
End Function