如题所述
如下:
472+503
=472+500+3
=972+3
=975
143+(57+26)
=143+57+26
=200+26
=226
78-46-14
=78-(46+14)
=78-60
=18
32×125
=4×8×125
=4×(8×125)
=4×1000
=4000
3×125×8
=3×(125×8)
=3×1000
=3000
47+51+49+53
=(47+53)+(51+49)
=100+100
=200