Answer: The two word phrase could be: "For Every"
When we are writing a ratio or fraction, we are comparing two different quantities.
Imagine that a track athlete has to run 3 miles for every day of practice. We could write the ratio 3:1.
Imagine that your parents are going to pay you $15 for every A on your report card. We could write the ratio 15:1
The key words are "For Every".