Two coins: A Zuz and an Istira.
The Talmud (Kiddushin f. 11b) instructs that an Istira is a half of a Zuz. An Istira is also referred to as a Trepik. Hillel earned one Trepik a day, half of which he used for the entrance fee to his Beth Hamidrash and the other half for personal expenses (see Yoma f. 35b). Rebbe Akiva worked in the lumber industry and brought wood to market earning one Zuz a day (see Avos D’Rav Nosson 6). These coins were also used as a form of measurement. This set is exactly as per the size referenced in the Talmud.