Evaluate $605+305$605+305 by doing the following.
Fill in the box with the missing number.
$605=600+\editable{}$605=600+
Fill in the box with the missing number.
$305=\editable{}+5$305=+5
Using the answers from the previous parts, solve $605+305$605+305.
Evaluate $306+604$306+604 by doing the following.
Using the fact that $201=200+1$201=200+1 and $309=300+9$309=300+9, evaluate $201+309$201+309.
Using the fact that $250=200+50$250=200+50 and $350=300+50$350=300+50, evaluate $250+350$250+350.