怎样简便就怎样计算 355+260+140+245 102×99 32×125 645-180-245   382×101-382 4×60×50×8.

问题描述:

怎样简便就怎样计算
355+260+140+245    
102×99      
32×125      
645-180-245      
382×101-382
4×60×50×8.

(1)355+260+140+245
=(355+245)+(260+140)
=600+400
=1000    
(2)102×99
=(100+2)×99
=100×99+2×(100-1)
=9900+200-2
=10098    
(3)32×125 
=4×(8×125)
=4×1000
=4000     
(4)645-180-245
=645-245-180  
=400-180
=220
(5)382×101-382
=382×(101-1)
=382×100
=38200
(6)4×60×50×8
=(4×50)×(60×8)
=200×480
=96000