一、口算。
$54 - 19 =$
$33×5 =$
$35 + 35 =$
$81÷3 =$
$56÷4 =$
$62×6 =$
$20×50 =$
$280÷4 =$
$22×30 =$
$155÷5 =$
$50×18 =$
$70×11 =$
$290×2 =$
$945÷9 =$
$13×60 =$
$800÷5 =$
$0×205 =$
$864÷4 =$
$\frac{2}{4} + \frac{1}{4} =$
$\frac{4}{9} + \frac{4}{9} =$
$\frac{6}{10} - \frac{2}{10} =$
$\frac{1}{5} + \frac{2}{5} =$
$\frac{6}{7} - \frac{3}{7} =$
$\frac{8}{9} - \frac{2}{9} =$

一、35 165 70
27 14 372
1000 70 660
31 900 770
580 105 780
160 0 216
$\frac{3}{4}$ $\frac{8}{9}$ $\frac{4}{10}$
$\frac{3}{5}$ $\frac{3}{7}$ $\frac{6}{9}$

二、用竖式计算，带*的要验算。
$19×65$
$60×42$
$*46×38$
$80×42$
$18×43$
$*65×85$

二、1235 2520 1748
3360 774 5525