Fill a jar with  jellybeans.
Ask the students to write on a slip of paper their estimates of how many jellybeans are in the jar.
They must sign the slips and deposit them in a folder.

Challenge kids to think of an easy way to discover the answer by thinking in terms of weight.
Use a scale that indicates either grams or ounces.
Have different children do the computations and record their findings on the chalkboard.

Follow these steps:

-Pour the beans on the scale and weigh them.
-Weigh a small paper cup. Fill it with beans and weigh it again.
-Subtract the weight of the cup to find the weight of the beans.
-Count the beans in this small sample.
-Divide the weight of all the beans by the weight of the sample.
-Multiply that answer by the number of beans in the sample to find the number of beans in the jar.

The game winner wins the jar.