Talk about what wouldn't fit. Talk about things that wouldn't need a container that large. Introduce the concept of estimating. Students will practice and refine estimating skills to develop number skills. Be sure that everyone has an opportunity to see the jar clearly.
Students record their estimate of the number of beans in the jar on their recording sheet.
Estimates can be graphed and a range determined. The jar is opened and the class counts the beans together to confirm the actual number. Students then write the actual amount and determine the difference between their estimate and the actual amount. Repeat the activity the next day with a different quantity. This activity should be repeated many times with many different objects and different sizes of jars.