(Mishnah): If at the top of the document, it said, "a manah (100 zuz)'', and below it said "200 zuz'', or vice-versa, we always follow the bottom amount.

If so, why was the amount written at the top? So that if one of the numbers of the lower amount would be erased, they could learn it from the top one.

(Gemara) - Beraisa: We can always learn the bottom one from the top one in a get mekushar and only when there is a discrepancy of one letter but not two...

Between the words chanan and chanani or between the words anan and anani, the document is valid and we learn the bottom from the top. But if it is a discrepancy of two letters, we cannot validate it.

Question (R. Yitzchak): If above said chanan and below said nani (meaning that above has an extra letter and below has a different extra letter), does below learn from above or above from below? (The Gemara does not answer the question.)