Mia compared one bean plant in each soil. What would help her check whether the height difference happens again?

• Choose the tallest plant and record only that plant's height each time
• Grow more beans but give each soil a different amount of water each time
• Grow several beans in each soil and repeat the fair comparison

What makes a test fair?

• Change several things together and measure only the quickest result
• Change one thing and keep other things that affect the result the same
• Keep the thing you want to test the same and change all the other conditions

To plan a fair test, decide what to change, what to measure, and what to keep the same.

Circle one:   True   False

Zara drops different types of ball from the same height onto the same floor to compare their bounce heights. What does she measure?

• How high each ball bounces after a drop
• How high she holds each ball before releasing it for a drop
• Which type of ball she chooses to release for each drop

Zara drops different types of ball from the same height onto the same floor. She measures how high each ball bounces. What does she change?

• The height she drops each ball from
• The type of ball she drops
• The floor beneath each dropped ball

After two weeks, a bean plant in garden soil is 11 cm tall. A bean plant in sandy soil is 6 cm tall. How many cm taller is the garden soil plant?

Answer: ______________

Ben compares ramp surfaces. The ramps have the same height and length. He releases the same toy car without a push and times it over the same distance. What does he change?

• The material on the ramp surface
• The height and length of each ramp
• The toy car released for each test

Tom gives Plant A more water and more sunlight than Plant B. Plant A grows taller. Can Tom be sure the water caused the difference?

• Yes, because the taller plant received more water
• Yes, because comparing two plants rules out all other causes
• No, because both water and sunlight changed