一、口算。
$600 - 300 =$ $30 + 80 =$ $120 - 30 =$
$600 + 600 =$ $320 - 40 =$ $500 + 90 =$
$730 - 700 =$ $130 + 400 =$ $270 - 200 =$
$29 + 32 =$ $1100 - 200 =$ $500 + 700 =$
$1100 - 400 =$ $2000 + 3000 =$ $250 - 70 =$
$50 + 60 =$ $140 - 70 =$ $300 + 5000 =$
$180 - 90 =$ $800 + 800 =$ $1500 - 700 =$
$600 + 50 =$ $1600 - 900 =$ $20 + 90 =$
$5700 - 5000 =$ $150 + 200 =$ $6000 - 4000 =$
$920 - 20 =$ $640 - 600 =$ $3000 + 5000 =$

一、300 110 90
1200 280 590
30 530 70
61 900 1200
700 5000 180
110 70 5300
90 1600 800
650 700 110
700 350 2000
900 40 8000

二、用竖式计算，带 * 的要验算。
$364 + 82$ $468 + 334$ * $564 + 343$

二、446 802 907