This document shows mathematical calculations working through various arithmetic problems. It starts with 2 x 8 x 4 = 16, then 3 x 8 = 24 and 24 x 4 = 64, showing 64 = 64. It continues through more calculations such as 7 x 8 = 56, 56 - 6 = 50, and 56 - 9 = 47, down to a final calculation of 15 - 18 = -3.