Tom bought five onigiri at the convenience store.
My friend was born on May 5th in the 55th year of Showa.
Once upon a time, there was a mother pig with five baby pigs.
This vocab is made from a single kanji, which means it shares the same meaning as the parent kanji: Five.
Since numbers are an exception, this word is read using the on'yomi reading even though it's made from a single kanji all alone. Luckily for you, you learned the reading for this word when you learned the parent kanji.