As part of our study of place value, I do a kinesthetic activity all year which seems to help everyone "get it" a little better.
I have digits written on construction paper and laminated: One number per piece of construction paper. I also have a piece with a comma that says thousand, a comma that says million, and a decimal point that says and.
I pass out the digits, commas, and decimal point randomly to students. Then I make up a number and tell the class. As I say the number, students with corresponding digits go to the front of the room to make the number. They line up and form the number for us by holding the card in front of their chest so we can see it. I usually let them collaborate some, but I really want them to do some independent thinking. It helps me to see who is still struggling with the concept. Once they think they are set, I have another student who didn't have a digit, read us the number. This is good practice for them as well.After we are done with that number, students hand out their digits to classmates who don't have one, and we start the whole process all over again.
Sometimes, when they have the number made, I will say "Let's reduce this number by 20,000." (or something like that) Then students have to figure out who is affected by this change and who would come take their place. It is a pretty good activity that we use all year long!