Increasing something by 5% and multiplying it by 1.05 are the same instruction, and a student who can say that has understood percent change rather than memorized a procedure. These free printable worksheets ask for that equivalence in all three directions.
If they get stuck
The answer key prints on a separate page.
The first direction is words to a multiplier: "increase a by 20%" is 1.2a. The second collects a sum into a single term: a + 0.2a is 1.2a, which is the line the standard itself works. The third runs backwards — 0.85a means 15% less — and it is the one students find hardest, because nothing in a bare multiplier says which way the change went.
The wrong options are the four real slips, not inventions. The part on its own (0.2a), the percent added as a number (a + 20), the multiplier the other way round (0.8a for an increase), and the percent read as a multiplier (20a). Each of those is an answer a student actually gives, and putting them beside the right one is what makes choosing a decision rather than a guess.
Read it in order, then say which way round