I had several students this past year who just couldn't get place value. I tried EVERYTHING that I could think of and was at my witts end! I was getting ready to do my grocery shopping one night and my husband ask me to pick
up some cheetos(sp) and suddenly it clicked--I could use food!!
I started by using the cheetos(I'm pretty sure that isn't spelled correctly, sorry) for the tens and soup crackers for the ones. Day one we simply would trade the tens for ones. I gave each student the value of 100 and we began by showing thirty three--three cheetos and three crackers. We did this for a while then we traded
one ten for ten ones. We did that until they "got it". We then moved into showing two numbers at the same time(twenty five and sixteen underneath) and traded in the tens for the ones. Once they were comfortable with this we began to add and subtract. It sounds pretty complicated but really it isn't and the kids love it!!
A word of advice--if you do this, ask parents to send in the snack to use as it can run into some money.