题目内容
用简便方法计算.
| 125×(8×4) | 125×(8+4) | 71×101 | 71×101-71 | 25×28 |
| 25×29 | 43×7+47×7 | 574+137+26+63 | 567+297 | 127×19-27×19. |
(1)125×(8×4)
=125×8×4
=1000×4
=4000
(2)125×(8+4)
=125×8+125×4
=1000+500
=1500
(3)71×101
=71×(100+1)
=71×100+71×1
=7100+71
=7171
(4)71×101-71
=71×(101-1)
=71×100
=7100
(5)25×28
=25×4×7
=100×7
=700
(6)25×29
=25×(30-1)
=25×30-25×1
=750-25
=725
(7)43×7+47×7
=(43+47)×7
=90×7
=630
(8)54+137+26+63
=(54+26)+(137+63)
=80+200
=280
(9)567+297
=567+(300-3)
=567+300-3
=867-3
=864
(10)127×19-27×19
=(127-27)×19
=100×19
=1900
=125×8×4
=1000×4
=4000
(2)125×(8+4)
=125×8+125×4
=1000+500
=1500
(3)71×101
=71×(100+1)
=71×100+71×1
=7100+71
=7171
(4)71×101-71
=71×(101-1)
=71×100
=7100
(5)25×28
=25×4×7
=100×7
=700
(6)25×29
=25×(30-1)
=25×30-25×1
=750-25
=725
(7)43×7+47×7
=(43+47)×7
=90×7
=630
(8)54+137+26+63
=(54+26)+(137+63)
=80+200
=280
(9)567+297
=567+(300-3)
=567+300-3
=867-3
=864
(10)127×19-27×19
=(127-27)×19
=100×19
=1900
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