| ①6.5×8+3.5×8-44 | ②907+907×9 | ③(999+111)÷[56×( - )] |
| ④56×99 | ⑤168.1÷(4.3×2-0.4) | ⑥[2-(11.9-8.4×1 )]÷1.3. |
=(6.5+3.5)×8-44
=10×8-44
=80-44
=36;
②解:907+907×9
=907×(1+9)
=907×10
=9070;
③解:(999+111)÷[56×(
-
)]=1110÷[56×
]=1110÷3
=370;
④解:56×99
=56×(100-1)
=56×100-56×1
=5600-56
=5544;
⑤解:168.1÷(4.3×2-0.4)
=168.1÷(8.6-0.4)
=168.1÷8.2
=20.5;
⑥解:[2-(11.9-8.4×1
)]÷1.3=[2-(11.9-
×
)]÷1.3=[2-(11.9-11.2)]÷1.3
=[2-0.7]÷1.3
=1.3÷1.3
=1.
分析:①、②、③、④能使用乘法分配律简便计算,⑤、⑥按运算顺序解答即可.
点评:此题考查按四则混合运算的顺序和使用运算定律进行简便计算.