Classroom space can be a problem; especially in the lower grades there are a lot of manipulatives. To solve space problems we buy small wash tubs and load them with things. They can be stacked quite neatly on top of each other. Then I use a marker to label the end of the tub so I can see at a glance which one I need. We also use a lot of coins. I saved the cups from pudding and loaded one set with 10 pennies and one with the 10 dimes (fake of course - who makes that kind of money?) and when math time comes I pass out the tub and each child takes one. I also use 2 liter bottles with the black base which I wash and cut off the top and load my unifix sticks into each.These can be passed down a row in a hurry. When done they make a 10 stick again and pop it right back in.