1830. This #kanjipuzzle is about evolution. Start with one character, add a few strokes, and get another, then repeat. 一 -> ? -> ? -> ? -> 番

Answer:

一 -> 十 -> 千 -> 禾 -> 番

一  ICHI, ITSU, hito(tsu) - one

十  JUU, tou, to - ten

千  SEN, chi - thousand

禾  The "Nogihen" radical - grain

番  BAN - number, watch, order