Re: How do i tell which is the independent variable in my science fair project?

Well, if you plan to keep the amount of cereal, milk and time constant, you could still change any of the following items as the independent variable:

the brand of cereal (General Mills, Post, Nabisco...)
the type of cereal (raisin bran, chex, fruit loops...)
the type of milk (skim, 1%, 2%, whole...)
the size of the cereal pieces (ground-up, halved, whole...)

if you decide to try more than one of these items, remember you should only change one at a time. So, if you are changing the type of milk, make sure to keep everything about the cereal constant so you can see the effect the milk has. Then, keep the type of milk the same across a set of samples and change one of the other variables. Your independent variable is always the one that you are changing, while keeping all the other factors the same.

I hope this explanation helps! Have fun with your experiments. ;)

Kieran