一、口算。
$48÷ 0.06=$
$205× 6=$
$16-0.16=$
$254-45=$
$0.6× 12=$
$77+7=$
$405÷ 9=$
$15.7+13.8=$
$10.5÷ 100=$
$2× 0.58=$
$0.04× 70=$
$7.61+2.39=$
$\dfrac{4}{9}× \dfrac{3}{4}=$
$\dfrac{3}{4}÷ \dfrac{3}{2}=$
$\dfrac{1}{5}-\dfrac{1}{6}=$
$0.5-\dfrac{3}{14}=$
$7÷ \dfrac{7}{15}=$
$\dfrac{9}{5}× \dfrac{5}{6}=$
$30× \dfrac{2}{5}=$
$\dfrac{9}{10}÷ \dfrac{1}{5}=$
$\dfrac{7}{24}× 0.75=$
$\dfrac{7}{5}÷ \dfrac{21}{10}=$
$\dfrac{3}{20}+\dfrac{1}{4}=$
$\dfrac{1}{24}÷ \dfrac{1}{12}=$

1.$48÷ 0.06=800$
2.$205× 6=1230$
3.$16-0.16=15.84$
4.$254-45=209$
5.$0.6× 12=7.2$
6.$77+7=84$
7.$405÷ 9=45$
8.$15.7+13.8=29.5$
9.$10.5÷ 100=0.105$
10.$2× 0.58=1.16$
11.$0.04× 70=2.8$
12.$7.61+2.39=10$
13.$\dfrac{4}{9}× \dfrac{3}{4}=\dfrac{1}{3}$
14.$\dfrac{3}{4}÷ \dfrac{3}{2}=\dfrac{1}{2}$
15.$\dfrac{1}{5}-\dfrac{1}{6}=\dfrac{1}{30}$
16.$0.5-\dfrac{3}{14}=\dfrac{2}{7}$
17.$7÷ \dfrac{7}{15}=15$
18.$\dfrac{9}{5}× \dfrac{5}{6}=\dfrac{3}{2}$
19.$30× \dfrac{2}{5}=12$
20.$\dfrac{9}{10}÷ \dfrac{1}{5}=\dfrac{9}{2}$
21.$\dfrac{7}{24}× 0.75=\dfrac{7}{32}$
22.$\dfrac{7}{5}÷ \dfrac{21}{10}=\dfrac{2}{3}$
23.$\dfrac{3}{20}+\dfrac{1}{4}=\dfrac{2}{5}$
24.$\dfrac{1}{24}÷ \dfrac{1}{12}=\dfrac{1}{2}$

二、把下面的二进制数改写成十进制数。
$(1101)_2$
$(11011)_2$
$(10010111)_2$
$(10100)_2$
$(101101)_2$
$(11000101)_2$

1.$(1101)_2=13$
2.$(11011)_2=27$
3.$(10010111)_2=151$
4.$(10100)_2=20$
5.$(101101)_2=45$
6.$(11000101)_2=197$