R. Chiya Rabbah and R. Shimon Bar Rebbi took equal portions in a firstborn. This is permitted on a weekday, meaning that on Yom Tov it is prohibited. This is because of the ruling in the Mishnah- one may not use scales at all.

R. Avun/ Rav Yehudah quoting Shmuel: Even to hang it on scales to protect it from mice is prohibited.

R. Yosi bei R. Bun: That is not the reasoning - rather, since the Mishnah teaches - 'a person may weigh out meat against a vessel or against a meat cleaver. The Chachamim say - one may not pay attention (use) to scales at all.' This means that there is another Tanna (who is not mentioned in the Mishnah) who reasons that it is permitted to hang it on scales to protect it from mice.

Beraisa (R. Shimon ben Gamliel): After they divide it, a person may even settle his mind by comparing the meat against a Litra measurement in order to know what he received.

This is like the story of R. Mana who bought carobs from the Shemita year (without weighing or measuring them, like the ruling of the Mishnah in Sheviis). He came to ask R. Chizkiyah, who told him - the Rabbanan follow the statement of R. Shimon ben Gamliel (i.e. you can now measure them in order to know how much you received).

Beraisa: A butcher should not weigh out with the meat in one hand and a Litra in the other, but he may cut the meat with a knife (even though he knows the weight of the meat he cuts).

Beraisa: On Yom Tov, one may not skin an animal whole, starting from its feet (as it is unnecessary effort) nor may one skin a firstborn or an invalid Korban in that way even during the week. (The reason for this will be explained.)

R. Avun: The reason for not skinning Korbanos in this way, is that it should not look like he is using the skin of Korbanos.

R. Yosta bar Shunam: Chazal decreed upon them lest they graze flocks (of firstborn and invalid Korbanos. If they would allow people to skin them in their entirety, people might begin to save the animals in order to use their skins later for themselves and they will be in danger of transgressing the prohibition of shearing or working the animals.)

R. Mana: All agree that to use a fan for skinning is permitted, as it does not involve much effort. But to beat the carcass as a way of skinning -

R. Chiya Rabbah and R. Shimon bar Rebbi disagree: One holds that it is prohibited and the other holds that it is permitted.

R. Yosi bei R. Bun (disagrees with R. Mana): All agree that it is prohibited to beat, but to use a fan -

R. Chiya Rabbah and R. Shimon bar Rebbi disagree: One holds that it is prohibited and the other holds that it is permitted.

(Mishnah): One may not sharpen a knife on Yom Tov but one may pull two knives against each other.

One may not say to a butcher, "Sell me a Dinar of meat''. However, one may slaughter it and divide it amongst them.

(Gemara): The Mishnah said, "One may not sharpen a knife on Yom Tov but one may pull two knives against each other.

Rav Chisda: The opinion who permits this is R. Yehudah.

Rav Yehudah quoting Shmuel: All agree that it is permitted as he is merely washing the knife to remove the fatty residue that is on it; he is not sharpening it.