一、口算。
$5.3-5.03= $ $3.1-2.9= $ $3.5×0.01= $
$60×0.65= $ $1.48-0.8= $ $2.05÷100= $
$0.75×0.6= $ $1.8÷0.3= $ $9.6÷0.32= $
$2.6÷1.3= $ $3.8+0.18= $ $1+3.89= $
$0.75×0.4= $ $30.4÷4= $ $1.2×6= $
$0.72÷0.6= $ $8.2+1.8= $ $100-35.22= $
$\frac {3}{4}-\frac {7}{24}= $ $1-\frac {4}{5}= $ $\frac {1}{6}+\frac {2}{5}= $
$1+\frac {2}{3}= $ $\frac {9}{4}+\frac {3}{4}= $ $\frac {1}{2}-\frac {2}{5}= $

 $5.3 - 5.03 = 0.27$
$3.1 - 2.9 = 0.2$
$3.5×0.01 = 0.035$
$60×0.65 = 39$
$1.48 - 0.8 = 0.68$
$2.05÷100 = 0.0205$
$0.75×0.6 = 0.45$
$1.8÷0.3 = 6$
$9.6÷0.32 = 30$
$2.6÷1.3 = 2$
$3.8 + 0.18 = 3.98$
$1 + 3.89 = 4.89$
$0.75×0.4 = 0.3$
$30.4÷4 = 7.6$
$1.2×6 = 7.2$
$0.72÷0.6 = 1.2$
$8.2 + 1.8 = 10$
$100 - 35.22 = 64.78$
$\frac{3}{4} - \frac{7}{24} = \frac{11}{24}$
$1 - \frac{4}{5} = \frac{1}{5}$
$\frac{1}{6} + \frac{2}{5} = \frac{17}{30}$
$1 + \frac{2}{3} = 1\frac{2}{3}$
$\frac{9}{4} + \frac{3}{4} = 3$
$\frac{1}{2} - \frac{2}{5} = \frac{1}{10}$

 

二、计算下面各图形的表面积。

6×6×6+2×2×4=232(cm²)
4×4×6-(4-2)×(4-2)×2=88(cm²)