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用简便方法计算:384-169-23125×99125×32×25123+279+177+321493-(126+93)61×101-61270÷4587×24+13×2425×(40-4)143×9-9×4393×199+93125×72.

题目详情
用简便方法计算:
384-169-231             

25×99           
125×32×25           123+279+177+321
493-(126+93)61×101-61        
270÷45                87×24+13×24
25×(40-4)143×9-9×43       
93×199+93             125×72.
▼优质解答
答案和解析
(1)384-169-231
=384-(169+231)
=384-400
=-16;

(2)25×99
=25×(100-1)
=25×100-25×1
=2500-25
=2475;

(3)125×32×25
=125×(4×8)×25
=(125×8)×(4×25)
=1000×100
=100000;

(4)123+279+177+321
=(123+177)+(279+321)
=300+600
=900;

(5)493-(126+93)
=493-126-93
=493-93-126
=400-126
=274;

(6)61×101-61
=61×(101-1)
=61×100
=6100;

(7)270÷45
=270÷(9×5)
=270÷9÷5
=30÷5
=6;

(8)87×24+13×24
=(87+13)×24
=100×24
=2400;

(9)25×(40-4)
=25×40-25×4
=1000-100
=900;

(10)143×9-9×43
=(143-43)×9
=100×9
=900;

(11)93×199+93
=93×(199+1)
=93×200
=18600;

(12)125×72
=125×(8×9)
=(125×8)×9
=1000×9
=9000.