Decently readable, though some of the letter forms you've chosen could be confused for others ('a' is quite similar to 'o', 'f' could be confused for 't'). When I'm lettering for engineering/math I use engineering gothic letterforms which avoid these ambiguities, among others (I vs l vs ι vs 1 vs 7, a vs α vs o vs ο, O vs 0, q vs g, k vs κ, v vs ν, u vs μ, B vs 8). When I'm handwriting I just write chickenscratch unreadable to anyone else including my future self after a year or so.