25x4=100；125x8=1000；25x16=25x4x4=100x4=400;25x48=25x4x12=100x12=1200.供参考。
简便计算, 25x4=100,125x8=100025x16=25x4x4=100x4=40025x48=25x4x12=100x12=1200
