Yes, math skills need to be up-to-date because computer science is all about abstraction and transferring information.

Mathematicians have the goal of describing a set of objects with a small set of properties. If you could describe any subset by listing elements and there’s no way an element from that subset couldn’t belong then the collection is called finite or well-defined or denumerable. So, if there are 100 people in a room, it would be denumerable to just say the first 20 seated at one table, what makes this different from mathematics? In mathematics, you deal with many sorts of number systems – whole numbers (including negative numbers), rationals.