# Video: Representing Three-Digit Numbers in Expanded and Written Forms

500 + 70 + 2 is the expanded form of 572. We can also write it in words as five hundred seventy-two. What is the written form of the expression 100 + 20 + 9?

02:02

### Video Transcript

500 plus 70 plus two is the expanded form of 572. We can also write it in words as five hundred seventy-two. What is the written form of the expression 100 plus 20 plus nine?

Here’s our expression 100 plus 20 plus nine. Let’s write this in the standard form. How many hundreds do we have? 100. How many tens do we have? Two. Two tens equals 20. How many units are ones place? Nine. In standard form, we have the digits one two nine.

Now, we need to take the standard form and write it in words. How do we write 100 in words? We spell out one: o-n-e, and then we write the word hundred: h-u-n-d-r-e-d. From there, we add the word twenty. We just spell t-w-e-n-t-y. Our units place is the nine. Nine is spelt n-i-n-e.

There’s another rule that we need to know and it’s about what happens when we write in words the tens and units place. In words between the tens and the units is a hyphen. So it’s 120 dash nine.

What is the written form of the expression 100 plus 20 plus nine? It is 129.