Here are some actually occurring numbers. Write them in scientific notation. Remember that there is one digit before the decimal point, and it is non-zero.
The land area of Earth is 57,500,000 = E ~ square miles.
The ocean area of Earth is 139,400,000 = E ~ square miles.
The length of a light year is 9,461,000,000,000,000 = E ~ kilometers.
This equals approximately 5,880,000,000,000,000 = E ~ miles.
The thickness of the skin of a soap bubble is approximately 0.0000001 = E ~ meters. (A meter is a little more than three feet.)
An ounce of Oxygen contains approximately
686,000,000,000,000,000,000,000 = E ~ molecules.