El Jeffe Pie Guide 10"

My sister in law and I have been debating for years how to properly cut cake and pie. This is a guide on how to do it. For example, if you have 7 people at your party, First cut from the exact center to the 1, then to each 7 on the plate, you'll end up with seven evenly cut pieces.

Mystery question: Do you know why the numbers 2, 4, and 8 are missing?

Another mystery question: Why do 3, 6, and 9 share a position on the board?

I also debated that the 1 position should be a 0, a bit of a reference to the 0 degree starting point on a 360 degree circle. but since we have often used this as a question of fractions, and a teaching tool, think of it this way:

For each lowest-terms rational number a/b, the integer b appears on the circumference at position 2pi a/b. In particular, the integer 1 should appear at 2pi 0/1. The cutting rule is then that you cut the cake at all positions marked with d for all divisors d of the number of people. If you are cutting for 9 people, you cut no