I have been trying to apply some conditional formatting to numbers which are formatted externally as fractions with a mask ???/???. In trying to test whether the fraction has a numerator of 1, I apply the formula = =MOD(1/G62,0)<>0, which divides 1 by the fraction itself, which ought to divide with no remainder if it has a numerator of 1, and return 0. If it returns something else then it has a numerator other than 1.
The rule is satisfied when it should not be. To test what is going on, I deconstruct the formula. The fraction 1/28 is divided into 1 to give 28 and this is correctly displayed. I then populate another cell using the formula =MOD(H62,1) to 28 and it gives 0, as it should. I do the same thing for 1/14 and the result is 1. In other words the MOD of 14, 1 is 1! When I look at the decimal representation of the 2 fractions( I imagine the fractions are actually the representations of the decimal numbers, which themselves will be binary or hex numbers internally), I see the following.
1/28 0.0357142857142856 1/14 0.0714285714285716
When the decimal for 1/28 is subtracted from the decimal for 1/14, the result is 0.035714285714286. As 1/28 can probably never be accurately represented in decimal, it looks like some rounding down has taken place. Most probably when MOD is applied to the decimal representation of 1/28 with 1, that decimal representation of 1/14 does not divide equally into 1, and this discrepancy is disclosed by the subtraction above.
I am using excel 2016. Maybe this is no longer a problem.
What I am trying to do is test to see if the lowest numerator of a fractional number is 1. Perhaps there is another way to do this in Excel. If so, let me know.
