In a three-digit number the digits go in columns.

Hundreds |
Tens |
Units |

Look at the number:

345

Put each digit in the columns like this:

Hundreds |
Tens |
Units |

3 | 4 | 5 |

So **345** is **three **hundred, **four **tens and **five **units, which is **three hundred and forty-five.**

And **504 **is** five **hundred, **no **tens and **four **units, which is **five hundred and four.**

Hundreds |
Tens |
Units |

5 | 0 | 4 |