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用简便方法计算下面各题99×78102×4679×25×4125×32×258×(125-20)800÷25÷44×95×12575×46+54×75.

题目详情
用简便方法计算下面各题
99×78            102×46           79×25×4        125×32×25
8×(125-20)800÷25÷4        4×95×125       75×46+54×75.
▼优质解答
答案和解析
(1)99×78
=(100-1)×78
=100×78-1×78
=7800-78
=7722;
(2)102×46
=(100+2)×46
=100×46+2×46
=4600+92
=4692;
(3)79×25×4
=79×(25×4)
=79×100
=7900;
(4)125×32×25
=125×(4×8)×25
=(125×8)×(4×25)
=1000×100
=100000;
(5)8×(125-20)
=8×125-8×20
=1000-160
=840;
(6)800÷25÷4
=800÷(25×4)
=800÷100
=8;
(7)4×95×125
=4×125×95
=500×95
=47500;
(8)75×46+54×75
=75×(46+54)
=75×100
=7500.