(10*1.11=11.1) evaluates as FALSE. How to correct it

Question

(10*1.11=11.1) evaluates as FALSE.

a = 10
b = 1.11
c = 11.1
\' (mathematically: 10*1.11=11.1)
debug.print a*b = c

I get False (incorrect) r

Answer 1

Floating point arithmetics is almost never correct, when .1 is involved. The reason is that .1 cannot be represented as a 1/2^n within 16 digits of n.

These are a few numbers, with which there would not exist problems in floating point, because they can be represented as 1/2^n:

• 0.125 = 1/2^3
• 0.5 = 1/2^1
• 0.375 = 1/2^2 + 1/2^3

Thus, the type decimal comes to solve the problem. This is the best way:

Sub TestMe()

    Dim a, b, c 'declaring as Variant, as Decimal cannot be declared in VBA

    a = CDec(10)
    b = CDec(1.11)
    c = CDec(11.1)
    Debug.Print a * b = c

End Sub