Answer:
The standard form for three million sixty thousand five hundred twenty is
3,060,520.
Explanation.
There are 520 hundred.
There are 60 thousand.
There are 3 million.
Hundreds contain 3 digits.
Thousands contain from 4 to 6 digits. Because a thousand exceeds 3 digits, a comma is used to separate the hundreds within a thousand.
A million contains 7 to 9 digits. a comma is used to separate the hundreds and thousands.
The picture below shows how the number 3,060,520 is split into the different categories.