一、口算。
$2.2 + 2.87 =$
$25 × 40 =$
$13.2 ÷ 10 =$
$60 ÷ 0.15 =$
$\frac{1}{2} × \frac{2}{3} =$
$\frac{3}{5} × \frac{8}{9} =$
$\frac{3}{4} + \frac{1}{2} =$
$0.9 ÷ \frac{3}{5} =$
$1.44 - 1.29 =$
$1.21 × 0.8 =$
$2026 - 1998 =$
$3.07 × 100 =$
$\frac{1}{2} ÷ \frac{4}{5} =$
$0.25 + \frac{5}{12} =$
$\frac{6}{25} × \frac{3}{4} =$
$\frac{3}{8} ÷ \frac{3}{8} =$
$260 ÷ 20 =$
$44.8 + 55.2 =$
$0.9 × 0.12 =$
$6.8 - 4.49 =$
$\frac{1}{4} ÷ \frac{2}{3} =$
$\frac{2}{9} ÷ \frac{3}{8} =$
$\frac{1}{2} + \frac{1}{8} =$
$\frac{2}{3} ÷ \frac{7}{6} =$

1.$5.07$
2.$1000$
3.$1.32$
4.$400$
5.$\frac{1}{3}$
6.$\frac{8}{15}$
7.$\frac{5}{4}$
8.$\frac{3}{2}$
9.$0.15$
10.$0.968$
11.$28$
12.$307$
13.$\frac{5}{8}$
14.$\frac{2}{3}$
15.$\frac{9}{50}$
16.$1$
17.$13$
18.$100$
19.$0.108$
20.$2.31$
21.$\frac{3}{8}$
22.$\frac{16}{27}$
23.$\frac{5}{8}$
24.$\frac{4}{7}$

二、用竖式计算。
15.8×3.14=
13.68÷8.55=
1.08×2.7=
15.58÷4.1=
4.24×3.15≈（得数保留一位小数）
8.09÷3.6≈（得数保留两位小数）

1.$49.612$
2.$1.6$
3.$2.916$
4.$3.8$
5.$13.4$
6.$2.25$