32÷4+2.5÷2.8
(1.75×3+1.75)×2.5
0.1×0.1÷(0.2+0.1-0.2+0.1)
0.08×2.7+0.08×6.3+0.08
(4.6÷0.2+0.8)×1.02
[(1.2-0.78)÷0.12+0.65]×0.8.
网友回答
解:(1)32÷4+2.5÷2.8
=8+
=8;
(2)(1.75×3+1.75)×2.5
=1.75×(3+1)×2.5
=1.75×4×2.5
=1.75×(4×2.5)
=1.75×10
=17.5;
(3)0.1×0.1÷(0.2+0.1-0.2+0.1)
=0.01÷[(0.2-0.2)+(0.1+0.1)]
=0.01÷0.2
=0.05;
(4)0.08×2.7+0.08×6.3+0.08
=0.08×(2.7+6.3+1)
=0.08×10
=0.8;
(5)(4.6÷0.2+0.8)×1.02
=(23+0.8)×1.02
=23.8×(1+0.02)
=23.8+23.8×0.02
=23.8+0.476
=24.276;
(6)[(1.2-0.78)÷0.12+0.65]×0.8
=[0.42÷0.12+0.65]×0.8
=[3.5+0.65]×0.8
=4.15×0.8
=3.32.
解析分析:(1)先算除法,再算加法;
(2)先算括号内的乘法,再算括号内的加法,最后算括号外的;
(3)先算括号内的,括号内运用加法交换律与结合律计算,然后从左往右依次运算;
(4)运用乘法分配律简算;
(5)先算括号内的除法,再算括号内的加法,最后算括号外的;
(6)先算小括号内的,再算中括号内的除法,然后算中括号内的加法,最后算括号外的.
点评:此题考查了小数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.