How It Works It looks a lot like a modern multiplication table. The top row and the far-right column contain the same 19 numbers: 0.5, the integers 1 through 9, and multiples of 10 from 10 to 90.

0.5; the integers from 1 to 9; and multiples of 10 from 10 to 90. As in a modern multiplication table, the entries at the intersection of each row and column in the matrix provide the results of ...