Things that can change


The statements below describe a number or different situations. What things vary or change in each case? Something that can change is called a variable.

1. The higher the temperature of water, the faster an egg will cook.

2. The time it takes to run a kilometre depends on the amount of exercise a person gets.

3. The temperature of water was measured at different depths of a lake.

4. Grass will grow taller if it is watered a great deal and is fertilized.


Sometimes a variable Is deliberately changed in a particular experiment. If so, it is called a manipulated variable. Read the statements below and identify the manipulated variable In each case.

5. The amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead.

6. lemon trees receiving the most water produce the largest lemons.

7. An investigation was performed to see if corn seeds would sprout at different times depending on the temperature of the water in which they were placed.


Sometimes a variable changes as a result or a manipulated variable. It is called a responding variable. Identify both the manipulated and responding variable in each of the following situations.

8. More bushels of potatoes will be produced if the Soil is fertilized more.

9. An investigation was carried out to determine if the number of nails picked up by an electromagnet will be increased if more batteries are put in the circuit.

10. Five groups of rats are fed identical diets except each group gets a different amount of Vitamin A. After three weeks on the diet, the rats are weighed.