Question

How do you convert `7.121 x 10^9` into expanded notation?

Answer 1

7,121,000,000

Explanation:

To expand out `7.121 * 10^9`, we can imagine moving the decimal place 9 times to the right and filling in any spaces with zeros:

`7.1210000000` (0 times)
`71.210000000` (1 time)
`712.10000000` (2 times)
`7121.0000000` (3 times)
`71210.000000` (4 times)
`712100.00000` (5 times)
`7121000.0000` (6 times)
`71210000.000` (7 times)
`712100000.00` (8 times)
`7121000000.0` (9 times)

To check, we know that `10^9` is a billion, so we expect the number to be in the billions and checking just by how many commas we add supports that.