文档介绍：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
99+(38+101)
=99+101+38
=200+38
=238
125×64
=125×8×8
=1000×8
=8000
500-99-1-98-2
=500-(99+1+98+2)
=500-200
=300
340+498
=340+500-2
=840-2
=838
436-99
=436-100+1
=336+1
=337
25×24
=25×4×6
=100×6
=600
65+(178+35)
=65+35+178
=100+178
=278
288-199
=288-200+1
=188+1
=189
850-246-54
=850-(246+54)
=850-300
=550
567-104
=567-100-4
=467-4
=463
260÷13÷2
=260÷(13×2)
=260÷26
=10
18×45
=45×2×9
=90×9
=810
101+202+303
=(100+200+300)+(1+2+3)
=600+6
=606
373-(173+40)
=373-173-40
=200-40
160
8×23×5
=8×5×23
=40×23
=920
720÷16÷5
=720÷(16×5)
=720÷80
=9
125×15×8×6
=(125×8)×(15×6)
=1000×90
=90000
25×32×125
=25×4×8×125
=(25×4)×(8×125)
=100×1000
=100000
125×(6×8)
=125×8×6
=1000×6
=6000
25×(4×12)×5
=(25×4)×(12×5)
=100×60
=6000
45×16
=45×2×8
=90×8
=720
898-133-67
=898-(133+67)
=898-200
=698
360÷8÷5
=360÷(8×5)
=360÷40
=9
(363+95)+(37+105)
=(363+37)+(95+105)
=400+200
=600
630÷35
=630÷7÷5
=90÷5
=18
560÷14
=560÷7÷2
=80÷2
=40
630÷42
=630÷7÷6
=90÷6
=15
25×(13×4)
=25×4×13
=100×13
=1300
35×14
=35×2×7
=70×7
=490
500÷25÷4