# Num.of_float 0.1;;
- : Batteries.Num.num = <num 1/1000>

Because of_float (batteries/src/core/extlib/extNum.ml) make some wrong assumption about printf behavior :

let s = Printf.sprintf "%f" 0.1 -> expect "0.1" but get "0.100000"

Well, the Num.num_of_string shipped with ocaml fails as well on decimal numbers... A poor man solution would be to strip
trailing zeros...