4. Write 365 billion in scientific notation. 5. Write 45 millionth in scientific notation.

To express 365 billion in scientific notation, you write it as \(3.65 \times 10^{11}\). This method makes it easier to work with large numbers by simplifying them into a format that highlights their scale. For 45 millionth, you would convert it to scientific notation as \(4.5 \times 10^{-8}\). This is a clever way to represent small fractions or decimals, making calculations much more manageable when dealing with tiny values.