php - Output currency after calculating (Sprintf)

i calculate via smarty like this:

{math equation='system - user' user=31.400 system=50.000}

The Output im getting is18.6but i want18.600

The Output should be like:

20.000 = ```20.000```<br>
400 = ```400```<br>
1.000,44 = ```1.000,44```<br>
Copy code

i tried it with different formats i saw on the sprintf manual but nothing helped.

Hope you can help me, thank you.