Slashed and crossed digits anywhere …?

Andreas Stötzner · January 26

I eventually came across digits (figures) which have a crossing slash, or even two or three, or a saltire on them. In Math and accounting literature they were used frequently and I would like to learn, if such notation is (or was) known in other fields.

Examples below: Type specimen book (Frankfurt 1834); Tartaglia: General Trattato de numeri… (16th c.); manuscript by G. W. Leibniz (17th c.).