working with numbers

[tempo]

i'm using 2 custom fields X and Y to calculate and display the Z value like this:

<setvar Z>(float)$threadfields['X']*100/(float)$threadfields['Y'] </setvar>
<td>{$tplvars['Z']}</td>

the problem is that the value of Z is 10.33333 (for example).

Can i rounding this Z value? (to show 10.5 for example)