一、口算。
$3000 + 200 =$ $1800 - 800 =$ $50 + 700 =$
$2000 + 500 =$ $4100 - 100 =$ $380 - 300 =$
$260 - 60 =$ $20 + 500 =$ $2000 + 600 =$
$1300 - 300 =$ $980 - 900 =$ $900 + 2000 =$
$4000 + 2000 =$ $600 + 40 =$ $7000 - 4000 =$
$1000 + 900 =$ $2200 - 200 =$ $9000 - 4000 =$
$600 - 100 =$ $850 - 800 =$ $2100 - 100 =$
$7000 + 300 =$ $9500 - 9000 =$ $40 + 900 =$
$200 + 600 =$ $790 - 700 =$ $1000 + 5000 =$
$3300 - 300 =$ $200 + 4000 =$ $2000 + 800 =$

一、3200 1000 750
2500 4000 80
200 520 2600
1000 80 2900
6000 640 3000
1900 2000 5000
500 50 2000
7300 500 940
800 90 6000
3000 4200 2800

二、用竖式计算。
$38 \div 9$ $29 \div 4$ $57 \div 8$

二、4……2 7……1
7……1