2020 Divisors Puzzle
This week's post is the entry I designed for the fall NJ Mathematical Association of America section puzzle contest. The contest is over, with five people successfully completing it on the day of the meeting.
It's based around the divisors of the number 2020. We only place clues between cells in the same cage, and not on the major grid lines. We place diamonds for when the sum of those cells divides 2020, squares for when the product divides 2020, and circles for when both the sum and the product divide 2020. Clues are placed whenever possible, so lack of a clue also reveals important information which you need to use in order to solve the puzzle.
Note that the act of using the year for this clue style isn't always a great idea. If we tried to use the same rule set for the year 2021, we'd be in a lot of trouble. Its only nontrivial factors are 43 and 47 so we would get no clues at all! The next year which really seems good for this style of puzzle is 2030, which is a bit of a wait.