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运算定律与 简算的整理

运算定律与 简算的整理. 找一找:谁和谁是好朋友?. 72. 51. 178. 125. 25. 263. 28. 163. 49. 8. 22. 4. 想一想,横线上应该填什么会使计算更加简便?你是怎么想的?. 25×137×. 4. 125×61×. 8. 练习一:简便计算. 107+158+93+42 487-139-61 (125+40)×8 25×44 3200÷25÷4 66×101-66.

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运算定律与 简算的整理

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  1. 运算定律与 简算的整理

  2. 找一找:谁和谁是好朋友? 72 51 178 125 25 263 28 163 49 8 22 4

  3. 想一想,横线上应该填什么会使计算更加简便?你是怎么想的?想一想,横线上应该填什么会使计算更加简便?你是怎么想的? 25×137× 4 125×61× 8

  4. 练习一:简便计算 107+158+93+42 487-139-61 (125+40)×8 25×44 3200÷25÷4 66×101-66 同桌之间相互交流一下,每道题分别运用了什么运算定律?

  5. 练习二: 25×444 25×444 =25×(400+40+4) =10000+1000+100 =11100 =25×4×111 =100×111 =11100

  6. 练习三:改错 8×50×2×125 =8×125+50×2 =1000+100 =1100 8×50×2×125 =(8×125)×(50×2) =1000×100 =100000

  7. 102×89 =(100+2)×89 =89×100+2 =8902 102×89 =(100+2)×89 =89×100+2×89 =8900+178 =9078

  8. 练习四: 李大爷家有一块菜地(如下图),这块菜地的面积有多少平方米? 8米 21米 19米 8米

  9. 思考: 小明在计算(□+50)×4时,算成 □×4+50,他的计算结果和正确结果相比,怎么样?

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