题目
怎样算简便就怎样算.
(1)
9× + ×9
(2)
(5.6﹣1.6÷2)×2.5
(3)
÷[ ×( + )]
(4)
12.5×2.5×32.
答案: 解: 9× 518 + 1318 ×9 =9×( 518+1318 ) =9×1 =9;
解:(5.6﹣1.6÷2)×2.5 =(5.6﹣0.8)×2.5=4.8×2.5=1.2×(4×2.5)=1.2×10=12;
解: 18 ÷[ 125 ×( 25 + 110 )] = 18 ÷[ 125×12 ] = 18÷150 = 18×50 = 254 ;
解:12.5×2.5×32 =(12.5×8)×(2.5×4)=100×10=1000