Hi Sandra,

I think you can do this in your head. If the room were 5 feet by 6 feet that would be $5 \times 6 = 30$ square feet. One box of planking has 19.8 square feet and thus 2 boxes will be between $2 \times 19 = 38$ and $2 \times 20 = 40$ square feet. Hence one box is not enough but 2 boxes is plenty. The room is a little more than 5 feet by 6 feet but even if it were 5 feet by 7 feet the area would be $5 \times 7 = 35$ square feet and two boxes is still plenty.

I hope this helps,
Penny