Numbers in Greek Papyri
In documentary papyri, a horizontal bar placed above or next to the Greek letter(s) will indicate a numerical value. Here are some examples from the Oxyrhynchus collection.
1) P.Oxy. 3340.5 (Senatorial Proceedings): ις̄ β[ο]υ̣λῆϲ = day 16, (there being a meeting) of the senate
2) P.Oxy. 2596.6-7 (Letter from Sarapammon to Andronicus): ταρίχουϲ ε͞ καὶ καθαροὺϲ δ͞ … / χαρτάρια β͞ = 5 salty fishes and 4 fine loaves … / 2 pieces of papyrus
3) P.Oxy. 3084.5 (Letter of Heraclius to Themistocles): τῆι κ͞δ ἑϲπέραϲ = on the 24th at evening
4) P.Oxy. 3096.2 (Complaint of an Error in Records): ϛ͞ φυλῆϲ γ͞ περιόδου = sixth tribe, third cycle
Theresa Chresand, Rachael Cullick, Marco Perale, Ryan Seaberg
Ancient Lives 
Regarding numbers, we learned that accents were applied to Greek letters to act as numbers only when the number was in a quantity of thousands. When did the accent concept update?