(someone) thinks small potatoes

Translations
(кто-то) считает мелочами
He thinks small potatoes when it comes to his achievements.
Он считает свои достижения мелочами.
Definitions
This phrase means that someone considers something to be unimportant, insignificant, or trivial. It suggests that the person views the matter as minor or not worth much attention.
Words
potato

noun
картофель
think

verb
думать
small

adjective
маленький