Q. Would Rav Miller know why in the traditional Talmudic Hebrew or Aramaic we use letters for numerals, when that makes it so awkward for doing any math? Didn’t our sages ever make elaborated mathematical calculations?
Just wondering,

A. Horav Shlomo Miller Shlit”a pointed out that Hebrew numerals are similar to the Greek numerals in that they represent numbers using the letters of the Greek alphabet These alphabetic digits are also known by names; Ionic or Ionian numerals, Milesian numerals, and Alexandrian numerals. In modern Greece, they are still used for ordinal numbers. The fathers of Mathematics and Geometry such as Thales of Miletus, Pythagoras, Euclid of Alexandria, Aristotle and Archimedes all used that system of ciphers very productively and successfully.

The Perush on the Rambam (Kidush Hachodesh 18: 13) reveals that the word Gimatrya itself is of Greek origin. As the Talmud (Megila 9b) teaches: The beauty (wisdom) of Yefeth (progenitor of Yavan) will dwell in the tents of Shem, we did not have to reinvent what others formulated. See also Rambam (Kidush Hachodesh 2: 4 and 9: 6) that Beis Din would calculate the complicated cycle of the moon in the way astronomers did. Then again, Kedushas Hachodesh (p. 94) maintains that the Rambam is referring to our own astronomers, such as Shmuel.
Although modern, Hindu – Arabic digits may be easier to use, employing the traditional Hebrew numeral system did not at all prevent our sages from reaching great mathematical knowledge and scientific wisdom.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a