Question

2.84×7.9+2.84×2+28.4×0.01的简便计算？

Answer 1

2.84X7.9十2.84X2十28.4X0.01＝2.84X7.9＋2.84X2十2.84×0.001
＝2.84X（7.9十2＋0.001）
＝2.84x（9.9＋0.001 ）
＝2.84X9.901

Answer 2

2.84x7.9+2.84Ⅹ2+28.4x
0.01＝
2.84Ⅹ7.9+2.84x2+2.84x
0.1
＝2.84x（7.9+2+0.1）
＝2.84×10＝28.4

Answer 3

这道题根据题目特点可以把28.4×0.01写成2.84×0.1，然后再用乘法分配律简便运算
2.84×7.9+2.84×2+28.4×0.01
＝2.84×7.9+2.84×2+28.4×0.01
＝2.84×7.9+2.84×2+2.84×0.1
＝2.84×（7.9+2+0.1）
＝2.84×10
＝28.4

Answer 4

2.84×7.9+2.84×2+28.4×0.01
=2.84×7.9+2.84×2+2.84×0.1
=2.84×(7.9+2+0.1)
=2.84×10
=28.4
这道题运用了乘法分配率

Answer 5

2.84＊7.9+2.84＊2+28.4＊0.01
=2.84＊7.9+2.84＊2+2.84＊0.1
=2.84（7.9+2+0.1）
=2.84＊10
=28.4