Cooking potatoes

Cooking potatoes

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about fair testing.
Neil set up the following experiment to find ways to speed up the cooking of a potato.
cooking potatoes experiment setup

Question 2Change answer

a)  Carefully explain two reasons why this is not a "fair test".
1.
2.

Question 2Change answer

b)  What two variables have been controlled for this experiment?
1. 
2. 

Question 2Change answer

c)  Neil re did this experiment and made it a "fair test".
What should Neil measure so he knows which potato cooks the fastest, and how could he do this?
Measure: 
How:
Task administration: 
This task can be completed with pencil and paper or online.
Copyright: 
Images (c) NZCER
Level:
5
Curriculum info: 
Science, Investigating in science, Material World
Keywords: 
changes, fair testing, variables
Description of task: 
From a diagram of an experimental set up, students answer questions based on fair testing principles. Questions cover the control of variables, and measurement of results.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
Capability: Gather and interpret data
This resource provides opportunities to discuss the importance of controlling variables when using fair testing for an investigation.
Science capability: Gather and interpret data (TKI)
Science capabilities: 
Gather and interpret data
Answers/responses: 

 

Y10 (10/2001)
a)

Any 2 of: 

  • Temperature (of water) is different.
  • Amount of water is different.
  • One potato is whole, the other is cut up (i.e., one has a greater surface area).

2 correct - very easy
 
1 correct - very easy
b)
  • Mass of potato.
  • Size of beaker.

2 correct - moderate
 
1 correct - very easy
c)

Measure: The softness of the potato.
How: Explains how softness could be measured, e.g., put masses/weights on to see, which leaves an indent on the potato.

very difficult
very difficult