I've just noticed that Raster Calculator delivers incorrect result in case there is at least one floating point multiplier in the transform formula.

For example, let's compare the following:

1. 1.5*B1 vs (3/2)*B1

(1.5*B1 results the same as B1 )

2. 2.99*B1 vs 3*B1 - I can see that 2.99*B1 results the same as 2*B1