Scientific notation is used to simplify very big or very small numbers.
In order to simplify this number, you need to do the following steps:
1. Count all of the digits to the right of the closest place to the left that has a value less than 10.
2. Write out your expression using this formula: a×10^x, Where a is the numbers you didn't count, and x being the number you counted.
I'm bad at explaining, so I'll show you some step-by-step examples.
Example 1:
450000000
count the digits to the right of the 4: there are 8
4.5×10^8
Example 2:
700000000000
count the digits to the right of the 7: there are 11
7×10^11
Sorry if this is confusing, again I'm not good at explaining things.
I hope this helps! Good luck!
(p.s., khan academy has some great videos on this)