脱式计算:0.75×18÷0.15; 2.07÷0.23÷0.45; 1.36÷0.8-12.9; 7.28+3.2÷2.5.
问题描述:
脱式计算:
0.75×18÷0.15; 2.07÷0.23÷0.45; 1.36÷0.8-12.9; 7.28+3.2÷2.5.
答
(1)0.75×18÷0.15
=13.5÷0.15
=90;
(2)2.07÷0.23÷0.45
=9÷0.45
=20;
(3)1.36÷0.8-12.9
=1.7-12.9
=-11.2;
(4)7.28+3.2÷2.5
=7.28+1.28
=8.56.
答案解析:(1)从左到右的顺序计算;
(2)从左到右的顺序计算;
(3)先算除法,再算减法;
(4)先算除法,再算加法.
考试点:小数四则混合运算.
知识点:此题考查的目的是理解掌握小数混合运算的顺序以及它们的计算法则,并且能够正确熟练地进行计算.