396X123=(400一4)x123=49200一492=48708 3.96X12.3=(14-0.04)12.3=49.2-0.492=48.708 68+44+32=68+32+44=100+44=144 125X764X8=125X8X764=1000x764=764000 1.25X76.4X0.8=1.25X0.8X76.4=1.25X0.8x76.4=1X76.4=76.4 99X38=(100-1)X38=3800-38=3762 9.9X38=(10一0.1)X38=380-3.8=376.2 357X1200+1200X643二(357+643)X1200=1000X1200=1200000 101X567=(100+1)X567=56700+567=57267 3.57X1200+6.43X1200=(3.57+6.43)X1200=10X1200=12000
396×123
=(400-4)×123
=49200-492
=48708
3.96×12.3
=(4-0.04)×12.3
=49.2-0.492
=48.708
568+44+32
=(568+32)+44
=600+44
=644
125×768×8
=(125×8)×768
=1000×768
=768000
1.25×76.8×0.8
=(1.25×0.8)×76.8
=1×76.8
=76.8
99×38
=(100-1)×38
=3800-38
=3762
9.9×38
=(10-0.1)×38
=380×3.8
=376.2
357×1200+1200×643
=(357+643)×1200
=1000×1200
=1200000
101×567
=(100+1)×567
=56700+567
=57267
3.57×1200+1200×6.43
=(3.57+6.43)×1200
=10×1200
=12000