Rocks and Their Properties: Weight   Day 3

We will explore the weight of rocks as another way to classify.  We know that rocks are different in colors and sizes. Today we are going to find out which rocks are the heaviest.


rocks of assorted sizes and weights                      
white glue
a worksheet with a scale drawn on it
a balance scale



1.   The children think of other ways that rocks are different besides their size and color and describe those attributes.

2.  Show several rocks. Today they will find out which rocks are the heaviest.

3.  Then by first looking, have students estimate which rock is the heaviest. To determine if students are aptly using powers of observation, a teacher picks up two rocks of different sizes.  The larger rock is picked up as if it was light as a feather, and the smaller rock is picked up as if it is extremely heavy. 

4.  Give students the opportunity to pick up the rocks to explore their weight.  Have the children take turns putting two rocks at a time in the balance scale to see which rock is the heaviest. Allow students the opportunity to experiment with the balance to determine how it is used, how to read the findings, and determine what combinations render what results.

5.  The students then draw a picture of a “light” rock and a “heavy” rock on their worksheet. Students discuss the connection between size and weight of rocks.

Closure:                                                               Follow up this activity by asking if the rock they thought would be the heaviest was in fact the heaviest. Also, is the biggest rock always the heaviest?  Question to leave with: Is the biggest object always the heaviest?  Challenge students to find 3 objects that are larger than others, but lighter in weight.


Rock Unit Overview

Lesson 1   Lesson 2  Lesson 4

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