Question

How many variables should be tested at a time. Explain why this is important.

Answer 1

you should only test one variable at a time, this variable is going to be your independent variable. if you change more than one thing you won’t be able to pinpoint the reason for results in your experiment. if you need more or an example let me know! ^_^

Answer 2

Answer: one variable

Explanation: This makes sure that the outcome is due to one identifiable factor.