想想,怎样才能算得快(请写出计算过程)

来源：百度知道 编辑：UC知道 时间：2024/06/04 20:22:17
125*2808
18.75-0.43-4.57-2.75
1.3*2.5*8*0.4*1.25
323*229-323*1291/2+1/6+1/10+1/20+1/30

125*2808
=125*[2800+8]
=125*2800+125*8
=125*8*350+1000
=1000*350+1000
=351000

18.75-0.43-4.57-2.75
=[18.75-2.75]-[0.43+4.57]
=16-5
=11

1.3*2.5*8*0.4*1.25
=1.3*[2.5*0.4]*[8*1.25]
=1.3*1*10
=13

323*229-323*129
=323*[229-129]
=323*100
=32300

1/2+1/6+1/10+1/20+1/30
=1/2+[1/6+1/30]+[1/10+1/20]
=1/2+1/5+3/20
=7/10+3/20
=17/20

1. 5X25X4X702====5X702X100===351000
2. 18.75-1.25-(0.43+4.57)====12.5
3. 3X2.5X4X1.25X8============300
4. 没看懂 是1291/2 还是129X1/2

57125*2808=125*8*351=351000
18.75-0.43-4.57-2.75= (18.75-2.75)-(0.43+4.57)=11
1.3*2.5*8*0.4*1.25=2.5*0.4*(1.25*8)*1.3=13

323*229-323*129=323*(229-129)=32300
1/2+1/6+1/10+1/20+1/30=1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6=1/3

125*2808=125*(2000+800+8)=125*2000+125*800+125+8=3510000
18.75-0.43-4.57-2.75
=18.75-2.75-(0.43+4.57)
=16-5
=11