To write the number two, one would simply combine two I's, resulting in II. The number three would be III, and so on. To write the number four, it is necessary to subtract one from five, resulting in IV. Similarly, to write the number nine, one would subtract one from ten, result...
(24) Ps. LXXXVII, 2. (25) Beth Midrash is here understood as the house of popular, aggadic lectures which, however, was not devoted to the study of Halachah. (26) In the Beth-hamidrash. (27) But for his living relies upon the support of other people. (28) Ps. CXII, I. (...