Essentially, you have to put any of the system's rounding expressions that suits your needs in front of your value.
Depending on your needs concerning the rounding, you would use one of the following:
1) Rounds up
ceil(value)[/code:29nwr85x]
2) Rounds down
[code:29nwr85x]floor(value)[/code:29nwr85x]
3) Rounds following mathematics rules
[code:29nwr85x]round(value)[/code:29nwr85x]
Also refer to the manual, system expressions, [i]math[/i] section.
scirra.com/manual/126/system-expressions