题目
脱式计算(能简便的要用简便方法计算)
(1)
36+64×85+15
(2)
0.4×9×25
(3)
61×40%+38× +0.4
(4)
2475÷45+2475÷55
(5)
(15﹣14× )×
(6)
+5.8﹣ +4.2.
答案: 解:36+64×85+15 =36+5440+15=5476+15=5491;
解:0.4×9×25 =0.4×25×9=10×9=90;
解:61×40%+38× 25 +0.4 =61×0.4+38×0.4+0.4=(61+38+1)×0.4=100×0.4=40;
解:2475÷45+2475÷55 =55+45=100;
解:(15﹣14× 47 )× 821 =(15﹣8)× 821 =7× 821 = 83 ;
解: 157 +5.8﹣ 87 +4.2 =( 157 ﹣ 87 )+(5.8+4.2)=1+10=11.