| 请写出过程 ①99×99+99 | ②10×0.1×100 | ③8÷8÷0.125 | ④37×39-29×37 |
| ⑤1.8÷2.7÷0.6×2.7 | ⑥47×99 | ⑦0.5+[ ÷(0.15+ )] | ⑧[( +2.1)× ]÷0.9. |
=99×(99+1),
=99×100,
=9900;
②10×0.1×100,
=1×100,
=100;
③8÷8÷0.125,
=8÷(8×0.125),
=8÷1,
=8;
④37×39-29×37,
=37×(39-29),
=37×10,
=370;
⑤1.8÷2.7÷0.6×2.7,
=1.8÷0.6,
=3;
⑥47×99,
=47×(100-1),
=47×100-47,
=4700-47,
=4653;
⑦0.5+[
÷(0.15+
)],=0.5+[
÷(0.15+0.45)],=0.5+(
÷
),=
+
,=
,=
;⑧[(
+2.1)×
]÷0.9,=(
×
+2.1×
)
,=(
+
)×
,=
×
+
,=
+
,=
,=1
.分析:①④⑥利用乘法分配律简算;
③利用除法的性质简便运算;
其余题目按照运算顺序解答即可.
点评:灵活应用乘法分配律及其逆运算来解题,使计算更简单.