1. 直接写出得数。
19.3 - 2.7 =
3.2 ÷ $\frac{1}{2}$ =
8 × 3.14 =
12 ÷ $\frac{3}{4}$ =
3.9 × 3 =
5.4 + 9 =
$\frac{1}{4}$ + $\frac{1}{3}$ =
1.25 × 8 =
6 ÷ $\frac{6}{7}$ =
$\frac{2}{15}$ ÷ $\frac{1}{10}$ =
$\frac{5}{12}$ ÷ $\frac{5}{6}$ =
$\frac{2}{5}$ ÷ 5 =

1. 19.3 - 2.7 = 16.6
3.2 ÷ $\frac{1}{2}$ = 6.4
8 × 3.14 = 25.12
12 ÷ $\frac{3}{4}$ = 16
3.9 × 3 = 11.7
5.4 + 9 = 14.4
$\frac{1}{4}$ + $\frac{1}{3}$ = $\frac{7}{12}$
1.25 × 8 = 10
6 ÷ $\frac{6}{7}$ = 7
$\frac{2}{15}$ ÷ $\frac{1}{10}$ = $\frac{4}{3}$
$\frac{5}{12}$ ÷ $\frac{5}{6}$ = $\frac{1}{2}$
$\frac{2}{5}$ ÷ 5 = $\frac{2}{25}$

2. 把下列分数化成百分数。
$\frac{1}{4}=$
$\frac{3}{4}=$
$\frac{1}{8}=$
$\frac{3}{8}=$
$\frac{5}{8}=$
$\frac{7}{8}=$
$\frac{7}{20}=$
$\frac{14}{7}=$
$\frac{1}{5}=$
$\frac{12}{5}=$
$\frac{4}{5}=$
$\frac{18}{5}=$

2. $\frac{1}{4}=$25%
$\frac{3}{4}=$75%
$\frac{1}{8}=$12.5%
$\frac{3}{8}=$37.5%
$\frac{5}{8}=$62.5%
$\frac{7}{8}=$87.5%
$\frac{7}{20}=$35%
$\frac{14}{7}=$200%
$\frac{1}{5}=$20%
$\frac{12}{5}=$240%
$\frac{4}{5}=$80%
$\frac{18}{5}=$360%

3. 递等式计算。
$\frac{3}{4}÷\frac{1}{6}+0.75×8$
$1\frac{1}{2}×8+1\frac{1}{2}×2$

3. $\frac{3}{4}÷\frac{1}{6}+0.75×8$ = $\frac{21}{2}$
$1\frac{1}{2}×8+1\frac{1}{2}×2$ = 15

4. 请画出从正面、左面、上面看到的形状。

4.