How to Salt Water Test a Dice

> A die should show a different number on top almost every time. If the same number or two are consistently showing on the top of the die, you have found the imperfections and you know you have a bad die.

How is this different from just throwing a die over and over and see what comes up? There's uncertainty in the outcome in both cases.

"Dice" is plural. A single one is a die.