(128x25)x4简便计算=128*25*4=128*100=12800
=128*(25*4)=128*100=12800
用简便方法计算125X25X4125X25X4=125*(25*4)=125*100=12500
解:125X25X4 =125X(25X4) =125X100 =12500朋友,还有不懂的地方,请追问,如果懂了,就采纳了呗.
利用乘法结合律,先把25x4结合在一起计算,再乘138最简便.计算步骤:138x25x4=138x(25x4)=138x100=13800
32*128x25=32x25*128=8*4x25*128=8*(4x25)*128=8*100*128=800*128=102400
125X128X25X25=125X8X16X25X25=125X8X4X4X25X25=125X8X(4X25)X(4X25)=1000X100X100=10000000
128x125x25=8x4x4x125x25=(8x125)x(25x4)x4=1000x100x4=400000
简便128x6+128x4128x6+128x4=128*(6+4)=128*10=1280
=11X(25X4)=11X100=1100