1. 三年级实践小组的同学参加卖书活动，5名同学卖了286本书，平均每人大约卖多少本？

2. 试着写出得数。
$121\div 6\approx$ $403\div 4\approx$ $181\div 3\approx$ $139\div 7\approx$
$543\div 9\approx$ $249\div 5\approx$ $235\div 8\approx$ $141\div 2\approx$
$122\div 6\approx$ $211\div 7\approx$ $719\div 9\approx$ $628\div 7\approx$