What number was the Tironian note visually similar to?
The remaining 20 Latin letters were supplemented by four more: ⟨æ⟩ (æsc, modern ash) and ⟨ð⟩ (ðæt, now called eth or edh), which were modified Latin letters, and thorn ⟨þ⟩ and wynn ⟨ƿ⟩, which are borrowings from the futhorc.