YOU SAID:

I went to the store and stole 5 20 carat diamond rings

INTO JAPANESE

私は店に行き、5 20カラットのダイヤモンドの指輪を盗んだ

BACK INTO ENGLISH

I went to the store and stole five 20 carat diamond rings

INTO JAPANESE

私は店に行き、5つの20カラットのダイヤモンドの指輪を盗みました

BACK INTO ENGLISH

I went to the store and stole five 20 carat diamond rings