4 5 x 12 25 July 8, 2019 16 32 64 128 4 15 5 12 x 8 25 4 x 25 12 x 5 170 chia 10 12 − 4 5 x 15 )= 25x 6 4 x 25 12 x 5 170 25 5 6 x 12 4 4 x 25 12 x 5 170 10 4 5 x 12 12 5 × 4