Question

If you are 20 years old,you have been alive for more than 630,000 seconds,write the last number in scientific notation?

630,000,000

I said it was 630,*10^7
idk how its wrong!

Answer 1

in scientific notation , we use a single digit followed by a decimal x a power of 10

so you want the decimal to be after the 6

6.2 x 10^8

that is,
assume that the decimal is at the end of
630,000,000.
Now count how many places I moved it to get to be after the 6

Answer 2

so the answer would be
630,*10^9?
or 630,*10^8
becuase 6.2x 10^8 it is saying its wrong.

Answer 3

It’s 6.3 x 10^8