Explain the scientific notation method of measurement.

Chemistry involves the study of atoms and molecules,which have extremely low masses and are present in extremely large numbers.
Chemists often deal with very large numbers,such as $602,200,000,000,000,000,000,000$ for the number of molecules in $2 \ g$ of hydrogen gas,or very small numbers,such as $0.00000000000000000000000166 \ g$ for the mass of a single $H$ atom.
To simplify calculations,scientific notation (exponential notation) is used,where any number is represented as $N \times 10^{n}$.
Here,$n$ is an exponent that can be positive or negative,and $N$ is a digit term varying between $1.000$ and $9.999$.
For example,$232.508$ is written as $2.32508 \times 10^{2}$,and $0.00016$ is written as $1.6 \times 10^{-4}$.
Multiplication and Division:
These operations follow standard rules for exponents.
Example (Multiplication): $(5.6 \times 10^{5}) \times (6.9 \times 10^{8}) = (5.6 \times 6.9) \times 10^{5+8} = 38.64 \times 10^{13} = 3.864 \times 10^{14}$.
Example (Division): $\frac{2.7 \times 10^{-3}}{5.5 \times 10^{-4}} = (2.7 \div 5.5) \times 10^{-3 - (-4)} = 0.4909 \times 10^{1} = 4.909$.
Addition and Subtraction:
For these operations,the numbers must first be converted to have the same exponent.
Example (Addition): $6.65 \times 10^{4} + 8.95 \times 10^{3} = 6.65 \times 10^{4} + 0.895 \times 10^{4} = (6.65 + 0.895) \times 10^{4} = 7.545 \times 10^{4}$.
Example (Subtraction): $2.5 \times 10^{-2} - 4.8 \times 10^{-3} = 2.5 \times 10^{-2} - 0.48 \times 10^{-2} = (2.5 - 0.48) \times 10^{-2} = 2.02 \times 10^{-2}$.