Is it 10 piece of leather? The original title should be watermelon cut into nine pieces with 4 knives, with skin 10. You can easily cut off five pieces of skin by just cutting a tic-tac-toe word. Cut from the middle, two pieces, one knife, then two pieces, two knives, * * * three knives, four pieces, and then cut one piece from the middle into two pieces, four knives, five pieces, of course, the skin is five pieces.