an acre has 4840 yd², and since a yard is 3 feet, a (yd)² is (3 ft)², or 3² ft² or 9 ft².
how many ft² are there in an acre? well, in 4840 yd² there are 4840 * 9 ft².
this golf course is 320 in area, since there are (4840 * 9) ft² in one acre, then 320 acres will be (320 * 4840 * 9) ft².
how many sections of 10,000 ft² are there? well, (320 * 4840 * 9) / 10000.
every 10000 ft² section is getting 40lbs of fertilizer, so the total amount of fertilizer is [ (320 * 4840 * 9) / 10000 ] * 40.
how many tons is that? well, there are 2000lbs in a ton, thus that'd be
[ [ (320 * 4840 * 9) / 10000 ] * 40 ] / 2000.
