How good are our senses at comparing the weights of the cubes?
1. Ask the question
Let students know that for the next four sessions they will be investigating weight. They will compare the weights of different things, including their materials cubes, and they will learn different ways to measure weight.
First explore students’ prior experience and understanding of weight:
- What is weight, anyway?
- What do you think is the heaviest object in this classroom? Why do you think so? How about the lightest one?
- How can we measure weight? What instruments for measuring weight have you seen or used? (Students might mention a bathroom scale, a doctor's scale with moveable weights, a hanging spring balance in the produce department, or perhaps a truck scale on the highway.)
- Are objects always measured in pounds?
Share the investigation with the class:
Tell students that their work today will help them start to answer this investigation question, but that they’ll not get a complete answer until after the next class class.
Note: In this session students will compare their sense of “felt weight” with that of others in the class. In the next session they will establish a weight order using a pan balance. Only then will they know how accurate their “felt weight” orderings are. Don’t tell the students about the pan balance at this point, but let them know that scientists usually work for a very long time before they can answer their own questions.
