脱式计算,能进行简便运算的要简便.
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/10/02 18:30:55
(1)7.6×40.3÷(76×0.8)÷1.25,
=7.6×40.3÷76÷0.8÷1.25, =7.6÷76÷(0.8×1.25)×40.3, =0.1×40.3, =4.03; (2) 5 1 5 ÷0.65- 1 5 7 ×0.875, =5.2÷0.65- 12 7 × 7 8 , =8- 3 2 , = 13 2 ; (3)(8.6- 7 4 7 )÷ 2 6 7 +7.64, =(8 3 5 - 7 4 7 )÷ 2 6 7 +7.64, =( 43 5 - 53 7 )× 7 20 +7.64, = 43 5 × 7 20 - 53 7 × 7 20 +7.64, = 301 100 - 53 20 +7.64, =3.01-2.65+7.64, =0.36+7.64, =8; (4)2.4×[ 2 1 3 ÷(2.4× 1 4 15 -3)], =2.4×[ 2 1 3 ÷( 76 25 -3)], =2.4×[ 2 1 3 ÷ 1 25 ], = 12 5 × 7 3 ×25, =140; (5) 456+123×321 123×322+333 +57 1 13 ÷7 , = 456+123×321 123×(321+1)+333 +57 1 13 ÷7, = 456+123×321 123×321+123×1+333 +57 1 13 ÷7, = 456+123×321 123×321+123+333 +57 1 13 ÷7, = 456+123×321 123×321+456 +57 1 13 ÷7, =1+57 1 13 ÷7, =1+ 742 13 × 1 7 , =1+ 106 13 = 119 13 . |