If a store advertised a sale that gave customers a 1/4 discount, what is the fractional part of the original price that the customers will pay?

It's easy to explain this using numbers - Let's say you buy something that costs $16. 1/4 of that is $4. 16 - 4 = 12.

12/16 = 6/12 = 3/4

Another way of explain this is using subtraction with fractions:

1 - 1/4 = 1/1 - 1/4 = 4/4 - 1/4 = 3/4

Therefore the customers will pay 3/4 of the original part.