Forums Scripts & Popups Equal to or greater than text match

I have a simple script:

on *:text:*math*:#:{
IF (*number >= .5*) {
/msg $me High number math
}
ELSEIF (*no math * iswm $1-) {
/msg $me No math
}
ELSE {
/msg $me Low math
}
}

My question is what do I put to cause any mention of any number from .5 upwards to trigger the IF section? I've highlighted the area I mean in red. Thanks for your help!