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I found the answers to the questions:
1. It is constructed with black numbers as times tables and red numbers as answers. The shape of it is a square.
2.The numbers in red are the answers.
3.The red 6 is in that square because the black number next to it is a 3, and the black number at the start of the row that the 6 is in is a 2, and 3x2=6.

I filled in the blanks: