**Addition** and **subtraction** of values written in scientific notation.

Example #1: When you add or subtract values in scientific notation they must have the same exponents.

If the exponents are not the same then we transform the __ smaller__ value so that they do.

Example #2: Using the method discussed above, determine the answer to the following question.

8.17 x 10^{8} + 1.25 x 10^{9}

Remember when adding or subtracting values that the final answer must have the least number of decimal places.

Example #3: Using the method discussed above, determine the answer to the following question.

9.08 x 10^{-11} - 1.17 x 10^{-12} - 3.35 x 10^{-13}