Question

There are 4 equally sized glasses with the same amount of water in them. 2 teaspoons of sand are poured into the first glass, two teaspoons of sugar into the second glass, two teaspoons of salt into the third glass and two teaspoons of flour into the 4th glass. Each mixture is stirred for the same amount of time.
What is being changed in the investigation (the independent variable) ?

Answer 1

The independent variable in this investigation is the type of substance (sand, sugar, salt, flour) that is added to each glass of water.