1000 $1s in 10 Envelopes

RAY: I'm going to give you a thousand $1 bills. You come up with 10 envelopes.

Here's your assignment: Figure out a way to put various numbers of dollar bills in those 10 envelopes, so that no matter what amount of money I ask you for, you can hand me some combination of envelopes and always be assured of giving me the correct amount of cash.

TOM: Let me get this straight. If you say, "Give me $637," I can say, "Oh, that will be envelope number one, envelope number six, and envelope number two."

RAY: You got it.

Think you know? Drop Ray a note!

[ Car Talk Puzzler ]