一、口算。
$\dfrac{2}{13}÷ \dfrac{1}{6}=$ $490÷ 70=$ $(\dfrac{7}{25}-\dfrac{1}{8})× 200=$
$8-3.6=$ $3.14× 0.9=$ $9-\dfrac{4}{7}-\dfrac{3}{7}=$
$96÷ 2.4=$ $1.02+0.48=$ $\dfrac{1}{7}× 11-\dfrac{1}{7}=$
$\dfrac{2}{5}+\dfrac{1}{14}=$ $\dfrac{2}{3}× \dfrac{7}{10}=$ $2÷ (\dfrac{1}{3}-\dfrac{1}{4})=$
$84÷ \dfrac{12}{7}=$ $12÷ 25\%=$ $1÷ \dfrac{1}{5}-\dfrac{1}{5}÷ 1=$
$\dfrac{2}{7}-\dfrac{1}{6}=$ $7.5÷ 30=$ $\dfrac{3}{4}× \dfrac{4}{3}÷ \dfrac{7}{8}=$
$0.25× 0.4=$ $\dfrac{9}{16}-\dfrac{1}{48}=$ $\dfrac{1}{2}× 3÷ \dfrac{1}{2}× 3=$

一、$\dfrac{12}{13}$ 7 31
4.4 2.826 8
40 1.5 $\dfrac{10}{7}$
$\dfrac{33}{70}$ $\dfrac{7}{15}$ 24
49 48 $4\dfrac{4}{5}$
$\dfrac{5}{42}$ 0.25 $\dfrac{8}{7}$
0.1 $\dfrac{13}{24}$ 9

二、计算下面各题，怎样简便就怎样计算。
$4.1+41× 9.9$ $25× 24× 3× 8$ $(4.2+\dfrac{6}{5})÷ (1.2-0.3)$
$\dfrac{4}{15}÷ [(\dfrac{3}{5}+\dfrac{3}{10})× \dfrac{4}{3}]$ $2026× 25\%+75\%× 2026$

二、410 14400 6
$\dfrac{2}{9}$ 2026