This week's learning is sponsored by Lynne Cassouto in loving memory of her mother, Ann Cassouto, Chana bat Moshe v'Henneh, as her 11 months of kaddish ends on Pesach. "She was deeply devoted to Jewish tradition, prayer, and text, and made sure her children received a strong Jewish education. She is forever missed, may her memory be a blessing for clal Yisrael." Today's daf is sponsored in loving memory of Anita Dinerstein, from her children and grandchildren on her first yahrzeit. “Her commitment to learning and the Jewish people continue to inspire us.”  Today's daf is sponsored by Mona & David Schwartz and family in loving memory of their mother and grandmother Mary Horowitz, Miriam Etel bat Aharon Halevi & Mirel on her 30th yahrzeit. "A woman whose home personified hachnasat orchim. May her neshama have an aliyah." Chizkiya says that maaser sheni produce that has less than the value of a coin can be redeemed on a coin that was used previously to redeem maaser sheni because there must be a little bit of value still left on the coin from the last time, as people aren't exacting in their calculations and generally use a bigger coin than what is needed. The Gemara questions this by bringing in a Mishna that implies that maaser sheni that gets mixed with non-maaser items is nullified in a majority. If Chizkiya is correct, then maaser should always be something that can never be nullified in a mixture because it can be fixed by redeeming, as per Chizkiya's suggestion, in which case it is a davar sheyesh lo matirin which can never be nullified. The Gemara tries to answer this question. A braita quoted in the discussion mentions two cases of maaser sheni that are nullified in a majority - less than and pruta and maaser sheni that was brought into Jerusalem and left Jerusalem. Why is maaser sheni brought into Jerusalem and then left unable to be redeemed (and therefore nullified in a majority)? After answering this question by establishing the details of the situation, Rav Huna bar Yehuda suggests an alternative reading of the braita. There is an amoraic debate regarding the premise of Chizkiya's ruling that maaser sheni that is less than a pruta cannot be redeemed onto a coin - is it when the principal is less than a pruta or the one-fifth is less than a pruta? In general, how is the one-fifth payment calculated - one-fifth of the principal or one-fifth of the total once the amount of the one-fifth is added (1/4)?