Fabric Requirements
You can use any number of like sized squares as long as the number of squares you use is divisible by nine.
Each group of nine squares will yield four disappearing blocks. For example if you begin with 36 squares to make four nine patch blocks, then these will yield a total of sixteen disappearing blocks.
To calculate the size of the finished block you need to multiply the size of your original squares by three, divide by two, then take off one. This will be the finished size of the block.
For example if you begin with 5-inch squares the calculation would be as follows.
5 x 3 = 15, ÷ 2 = 7½ - 1 = 6½ inches.
6-inch squares would yield 8-inch blocks, 7-inch squares would yield 9½- inch block
Hope this helps you figure what you need.
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