0.25 means that the result will be 1/4 of the final equation, but 1-0.25 means 3/4 will be left. It’s important to have the word equation specify which, as you get two different results. A context in which you’d need the .25 is when it asks for a specific amount (how much is 25% of...), and the 1-.25 is in the context of a discount. (25% off...)
