Abbreviating with 7 and 9

Q

How did 7 come to be an abbreviation for 'and' in Old English?
https://www.quora.com/How-did-7-come-to-be-an-abbreviation-for-and-in-Old-English/answer/Hans-Georg-Lundahl-1

Answer requested by

Praveen Upadhyay

Hans-Georg Lundahl

just now

amateur linguist

Jane Wickenden answered.

If you have trouble clicking her links, think of an E and a T attached into the middle bar, then omit a few bars, the top bar of the T is then longer to the left than the right and omit the shorter right, it looks like 7 (except it’s not diagonal in the hasta, the line going down).

This means, 7 will do as an approximation of Tironian et. Like 9 for another sign:

• A mark, resembling the Arabic numeral 9 or a mirrored C in Gothic texts, is one of the oldest signs and can be found in the texts of Marcus Valerius Probus and Tironian notes with the same meaning as con.
• Another mark, similar to a bold comma or a superscript 9, placed after the letter on the median line, represented us or os, generally at the end of the word, being the nominative case affix of the second declension, sometimes is or simply s. The apostrophe used today originated from various marks in sigla, which caused its current use in elision, such as in the Saxon genitive.

Scribal abbreviation - Wikipedia