If I did my math correct it should be 47. If you take 284x386 you get 109,624 (that should be the area in square feet) then take 109,624 and divide it into 2346 and you get 46.7280477408. In order to cover it you should round up to 47 bags.
This is like late elementary/early middle school stuff where you learn this.
First off, what number is in the position of the hundereth place? 0? No. 1? No. 5 yes! Now how i learned how to round is you take the number to the right of whatever you are being asked about and round it up or down. Now if the number (in this case it is 1) is lower than 5, you round down (or keep it the same) but if it is 5 or higher you round up. since 1 is lower then 5, that 5 in the hundereths place stays the same.
The surface area is 480 :)
I believe the answer is 4