A student about to graduate High School just finds out that his Math teacher gave him a failing grade. He does not want to go to summer school, and thinks he deserves a passing grade. His teacher gives him one last chance to earn the passing grade. He gives him some words, fractions, definitions, a question, a group of whole numbers, and two phrases. They are:

Square, Ellipse, Four-sided Polygon, One-sided, Ellipse, How many people inhabit the Moon?(Zero is not acceptable), Trapezoid, Isosceles, 1/26, 12/26

And the group: 5.8, 1, 3, 4, 2.5

He also says: "What A is to the Alphabet becomes greater."

The teacher tells the student that the things he has given him, when understood properly, will lead him to do something with the number group. The student is allowed 1 minute to figure out what to do with this group. What is it? Does he eliminate the decimals? Does he eliminate the whole numbers? Or perhaps he has to isolate the numbers that are related in some other way?

Well, this student REALLY doesn't want to spend his summer making up math class. He is able to solve the problem with 5 seconds left on the clock.

What did the student do with the number group based on the information provided by his teacher to get that passing grade?