To find the price Nolan has to pay after applying a 25% discount, he should multiply the original price by \( (1 - 0.25) \).
This calculation can be simplified:
\[ 1 - 0.25 = 0.75 \]
So, Nolan should multiply the prices on the tags by 0.75 to find the price he would have to pay, before tax, in one step.