Some Rocks are Heavier Than Others, Lesson 3 - Rocks Unit
Grade Level(s): K, 1-2
By: Jane, Kindergarten Teacher

We know that rocks are different in colors and sizes. Today we are going to find out which rocks are the heaviest.

Materials:

• rocks of assorted sizes and weights
• white glue
• a worksheet with a scale drawn on it
• a balance scale - I have used 2 chairs with a pole between them and a clothes hanger across the pole. I punch holes in 2 plastic cups with a hole puncher and attach the cups to the hanger with string. I then move the strings back and forth on the hanger until the cups are pretty well balanced.

Plan:

1. Can the children think of other ways that rocks are different besides their size and color?
2. Show several rocks. Tell them today we will find out which rocks are the heaviest.
3. Have the children try to tell by first looking and then by feeling which rock will be the heaviest and which one will be the lightest.
4. Have the children take turns putting two rocks at a time in the balance scale to see which rock is the heaviest.
5. They then draw a picture of a light rock and a heavy rock on their worksheet.

Comments:

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? You can also add a section to this unit on smooth and rough rocks. To culminate the unit, we go back to the chart and answer what we learned about rocks. Good luck and have fun!

Related Pages:

Making a Rock Collection, Lesson 1 - Rocks Unit ( K, 1-2 )
To present the concept, Rocks Can Be Different Sizes.

Rocks Are Different Colors, Lesson 2 - Rocks Unit ( K, 1-2 )
Examine different rocks and find the many different colors in each and then compare these rocks with other rocks.