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

1 Answer
Aug 1, 2018

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.