Actually modern zakat of 2.5% and the rest of the percentages (like 10%) are more closely linked to Jewish tradition.
I have asked the same question to a Rabbi on Facebook, who is knowledgable in Jewish-muslim relations (Rabbi Ben Abrahamson)
Q. Question about Zakat? Is there any connection between the tithe, and the Islamic 2.5% zakat? Is there ever mention of 2.5% in Judaic tradition? I only came across the tithe in the Torah?.
A. The word Zakat probably derives from Zedakah. Today Zedakah in Hebrew means Charity, but during the Second Temple times it was a tax. There were several taxes, the 2% (1/50) or 2.5% (1/40) tax was called Terumah. The Mishnah, Tosefta, and Gemara, include a tract entitled Terumot ("Offerings"), which deals with the laws regulating raised offerings. According to Jewish Law, the "great offering" (terumah gedolah) could only be separated from the non-tithed produce (tevel), and "tithe offering" (terumat maaser) only be separated from "first tithe" (maaser rishon), by its owner, or an authorized, legally permissible agent; minors, deaf-mutes, the mentally ill and non-Jews were not obligated to perform such separation (Terumot 1:1). However, while non-Jews could not act as agents for Jews to separate terumah, the terumah owned by and separated by non-Jews was considered valid and had the status and sanctity of terumah (Terumot 3:9). Based in part on the measures described by the prophet Ezekiel, Jewish Law set the minimum amounts of the "great offering" at 1/60 of the finished produce for a poor person, 1/50 for the average person, and 1/40 for the generous. The "tithe offering" (terumat maaser) was always 10% of the "first tithe" (maaser rishon).
The Talmud opens with a discussion of when the Shema Yisrael ("Hear O Israel") prayer should be recited. The Mishnah states that it should be recited when priests who were "unclean" (tamei, טָמֵא ritually impure) are able to enter the Temple to eat their terumah raised-offering (Brachot 2a). This passage is one many which intimately connect the daily rituals of Orthodox Judaism with details of the rhythm of the life of the Temple in Jerusalem.
Also 5 salat also seems to resemble jewish prayers.
http://www.alsadiqin.org/history/Prayer%20Positions.pdf