Question 1060007
Write a proportional here.
The fractions will be part over whole.
Bushels will subside in the denominator of the fractions.

{{{ 51/1224 = x/1560}}}

Solve for "x". 
Cross multiply 51 times 1560 and divide by 1224. 
51*1560 = 79,560
79,560 / 1224 = 65

1,560 bushels can be placed in 65 acre fields.

Great, although, the question asks how many ADDITIONAL acres of field must be planted.

Subtract the original acre amount from 65 to get the final answer.

65 - 51 = 14

14 additional acres must be planted.