Volume unit mistake, in

[MG_10472771]

That is the mistake  //Mathcad 14

[Werner_E]

In the for-loop you did not wrote the number 1 but rather a lower case l (which Mathcad interprets as unit liter).

Once you correct this typo, your function works OK.

You may consider making the function independent on the current setting of ORIGIN:

or

[ValeryOchkov]

In Russian texts

...переменная с именем 1 (эль)...