How Do I Perform A Science Fair Project On Which Takes More Water A Shower Or Bath?

I think the you first should set up a boundary with time. An example could be: When I'm I fully clean and how long time does it take? 5 minutes? If yes then set up the time, close the water from letting go, shower and at the end use a bucket to scoop the water and count how many buckets. The same principal you'll use when bathing. Cheers

A bath uses more water than a shower.  To demonstrate this, next time you take a shower, close the bath tub drain and see how much water collects during your usual shower.

A bath is always filled with water to the top it uses more water

A bath clearly uses more water than a shower!

No a normal shower uses less water unless it's a power shower then it uses around the same water as the bath within the first five minutes

Try it out and see. It would be a easy experiment to do

I think a bath be-because when you put The stopper in the tub it holds the water in the tub and the shower you don't put the stopper in the tub