Tom mulai bermain biola ketika dia berumur tigabelas tahun.

English Translation

Tom started playing the violin when he was thirteen.

Typo: it should be “tiga belas” in two words.

The Indonesian sentence was updated by the Clozemaster admin on September 25, 2022.

Old: Tom mulai bermain biola ketika dia berumur {{tigabelas}} tahun.

New: Tom mulai bermain biola ketika dia berumur {{tiga}} belas tahun.

I don’t believe that {{tiga}} (meaning: “three”) is the most difficult word based on the word frequency list.

Also, 50K Most Common Collection incorporated the updated one, but Fast Fluency Track hasn’t done yet.