题目内容
| 怎样简便就怎样计算 28.4×101-28.4 |
3.6×201 | 3.5×0.7+5.5×0.7+0.7 |
| 4×0.8×12.5×2.5 | 17.5÷0.25×17+13 | 0.94×2.5-0.45 |
分析:①②③运用乘法的分配律进行计算即可.
④运用乘法的结合律、交换律进行计算即可.
算式⑤、⑥根据四则混合运算的运算顺序计算即可.
④运用乘法的结合律、交换律进行计算即可.
算式⑤、⑥根据四则混合运算的运算顺序计算即可.
解答:解:①28.4×101-28.4
=28.2×(100+1)
=28.2×100+28.2×1
=2820+28.2
=2848.2;
②3.6×201
=3.6×(200+1)
=3.6×200+3.6×1
=720+3.6
=723.6;
③3.5×0.7+5.5×0.7+0.7
=(3.5+5.5+1)×0.7
=10×0.7
=7;
④4×0.8×12.5×2.5
=(0.8×12.5)×(4×2.5)
=10×10
=100;
⑤17.5÷0.25×17+13
=70×17+13
=1190+13
=1203;
⑥0.94×2.5-0.45
=2.35-0.45
=1.9.
=28.2×(100+1)
=28.2×100+28.2×1
=2820+28.2
=2848.2;
②3.6×201
=3.6×(200+1)
=3.6×200+3.6×1
=720+3.6
=723.6;
③3.5×0.7+5.5×0.7+0.7
=(3.5+5.5+1)×0.7
=10×0.7
=7;
④4×0.8×12.5×2.5
=(0.8×12.5)×(4×2.5)
=10×10
=100;
⑤17.5÷0.25×17+13
=70×17+13
=1190+13
=1203;
⑥0.94×2.5-0.45
=2.35-0.45
=1.9.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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