petica

1. (at school) a five; top mark; an A
   Dobio sam peticu iz matematike! — I got a five in maths!
   Ona ima sve petice na kraju godine. — She has straight A's at the end of the year.
2. the number five; the figure 5
   Tvoja petica liči na šesticu. — Your five looks like a six.
3. colloq. (bus, card etc.) the number five
   Do centra idem peticom. — I take the number five into town.

In Serbian schools 5 is the top grade and 1 is a fail.