Answer :
well I divided 20,400 by 10 which got 2,040 so 2,040 grapefruit were shipped
10 grapefruit in each box. If the grower shipped 20,400 boxes. You would have to multiply to find out the total number of grapefruit.
20,400 boxes times 10 in each box.
20,400 x 10 = 204,000
204,000 grapefruit were shipped.
Hope this helps. :)