[plt-scheme] Division error in DrScheme v.4.1

> When i'm calculating an expression wich returns integer values, like (/ 45
> 5) or (/ 32 8), all goes just fine. But when i'm operating with fractions,
> like (/ 4 23) or (* .04 6), DrScheme returns me an error instead and
> crushes, error is

I'm running DrScheme/mzscheme v4.1 [3m], when I choose the "Beginning
Student" language and apply those functions I get:

> (/ 4 23)
0.1739130434782608695652
> (* .04 6)
0.24
>