Alright I know how to round a number, but ... I don't know what else to call this.

I get a number simular to 308,916.82 ... I don't have a problen doing th math to round that up ... Math.ceil ... my problem is making that number flat to the next position down like: 310,000. So if I had 1152 i'd want it to be 1200. If I had 4,500,345 I'd want 4,600,000. Make sense?

I hope so ... can anyone help me with this?