
Currently, I am using Everyday Mathematics in my classroom. This program is loaded with wonderful hands on activities for the children. The publisher also supplies all necessary manipulatives and games.
This is an activity that Deb Smith sent in.
This is an activity that I do in second grade that could easily be made easier or harder depending on your grade level.
Read How Many Feet in Bed? or The Foot Book or How Many Feet in Bed? or The Foot Book or How Big is a Foot?
Then pose the question how many feet in our classroom? How many kids? How many people? How many feet. Make sure you say and write:
One person has two feet. There are ______ people in our classroom. There are ______ feet in our classroom.
Tell the kids to use pictures, numbers, and words to figure out the question.
 Now, some helpful hints as the teacher 
First of all your goal is not the "right" answer. It is instead the process of figuring out. Can your children count by twos? Or do they count 12 34 56 78. Do the children give each person 2 feet or one?
Once they start, give them a good 5 minutes of struggling to work it out. If they give you an answer (or even shout it out) say, "I don't want just a number. I need you to show me with pictures numbers and words."
Some kids will only be able to say 20 kids so 40 feet. Then they get stuck. I oneonone encourage them and get them to talk out their process. How do you know that? Did you count onetwo threefour? Did you count two four six... if they say they counted by twos, have them count by twos to you. They MIGHT have but most kids don't.
Also get them to label how they counted.
I have the kids draw a head with two legs sticking out at the bottom (ok guys, I know I know developmentally inappropriate but hey  this is math class!)
The PROCESS of problem solving is the goal, not the "right" answer. It is important to look beyond what is written on the paper and look into what the thoughts are. This type of story problem solving is much more thought provoking and math stretching.
