MOD function issue

Question

=MOD(0.6*3*25, 1) then the value is 1;

=MOD(0.6*25*3,1) then the value is 0.

Why?

Answer 1

I don't understand why intermediate results affect the final results

Answer 2

Illustrated a different way without using MOD:

=LET(Number, 0.6*3*25, IntermediateResult, Number / 1, IntermediateResult - TRUNC(IntermediateResult)) = -7.10542735760100E-15

=LET(Number, 0.6*25*3, IntermediateResult, Number / 1, IntermediateResult - TRUNC(IntermediateResult)) = 0.00000000000000E+00

Kevin

Answer 3

That is the same result I got. But when I looked at the result of the MOD function, that's where the significant digit noise was introduced. So, while the intermediate result appears to not have any noise, it is in there and the MOD function is picking it up.

Kevin

Answer 4

I checked the value as following:

=if(0.6*3*25=45,"yes","no")

It returned yes, which means no rounding issue.

Answer 5

You have run into a rare but real issue of significant digits and rounding. It isn't clear where the significant digit noise is creeping in but it is.

The actual results of the MOD function, when enough significant digits are displayed, are:

0.999999999999993000000000000000000000
0.000000000000000000000000000000000000

Kevin