The image below shows the correspondences between the Syriac letters used as numerals and the Coptic numerals, which are also occasionally found in Syriac and (more commonly) Arabic manuscripts for foliation or quire-marking. Note the incongruity of position for the two systems: the Coptic numerals are right-side-up, but most of the Syriac letters are turned sideways. The manuscript is a liturgical book from Saint Mark’s Monastery, Jerusalem, which recently partnered with HMML to digitize its collection, and these numerals are written out at the bottom of the first folio, without any apparent connection to the text itself; they are written again (without the Syriac correspondences) on the inside front wooden board of the book.
Some references for the use of Coptic numerals in manuscripts:
A. Gacek, Arabic Manuscripts: A Vademecum for Readers, p. 118.
W.H.P. Hatch, Album of Dated Syriac Manuscripts, p. 23.
H. Ritter, “Griechisch-koptische Ziffern in arabischen Manuskripten,” Rivista degli studi orientali 16 (1936): 212-214.
W. Wright, Catalogue of the Syriac Manuscripts in the British Museum, vol. 3, p. xxvi.