Question

What is the expanded form of 430,290,100

Answer 1

You would break each part down as if it was an addition problem....
400,000,000+30,000,000+200,000+90,000+100

Answer 2

So,

When you write a number in expanded form, you separate each non-zero digit and write it according to its place value.

430,290,100

400,000,000
30,000,000

We don't put anything for the millions place because there are none.

200,000
90,000
100

Then we join each of them with a plus sign.

400,000,000 + 30,000,000 + 200,000 + 90,000 + 100