Groups, arrays, factors and sharing out — and several boards where multiplying is something you do to a position rather than to a pair of numbers on a page.
Disco Balls takes a number apart into primes and asks for every order they can be multiplied in, each drawn as its own picture of the same dots. Mondrian Puzzle, Picasso Brush and Galaxea each make a rectangle the unit of play, so every move is a multiplication you have to do before you know what you have made. Gozen forces the next number on you and lets you choose only where it stands, so shared factors decide whether it survives the turn. Zebra and Balanced Zebra multiply your own herd sizes together, which is where the useful surprise is: three threes beat one nine, and a stone standing alone is worth nothing at all. Diversity City ends in a division: every zone’s number added up and shared out over the zones. A zone scoring below the average pulls it down, unless it lifts its neighbours by more, so the puzzle is learning what moves an average.