He studied rabbinical literature in Bonn and Frankfurt am Main, then in Krakow under Moses Isserles. Later he attended the lectures of the Maharal of Prague and of his brother, Rabbi Sinai. He lived for a time at Nordheim (where he studied Euclid), passed several years in his native city of Lippstadt, and then in about 1564 settled at Prague.
He is the author of "Tzemach David" (1592). They introduced philosophy, mathematics, and astronomy into the circle of their studies, and from them Gans received the impulse to devote himself to these branches of science. There he came into contact with Kepler and Tycho Brahe, and took part for three consecutive days in astronomical observations at the Prague observatory.
He also carried on a scientific correspondence with Johann Müller (Regiomontanus), and was charged by Tycho Brahe with the translation of the Alfonsine Tables from Hebrew into German.
His grave in Prague is marked with a Star of David and a goose (German: Gans meaning goose in German). This is the first time a Star of David was officially used as Jewish community emblem.