0.98 + 45.102 + 32.3333 + 31 + 0.00009 = _________.

There are two ways to solve this question. First, you can add all the given numbers and find the exact answer. This method is time-consuming and less efficient.
The second method to solve this question is by adding only the numbers on the left of the decimal and then comparing your answer with the answer choices that you are given. We add 45, 32, and 31 to get 45 + 32 + 31 = 108. Therefore, the answer must be close to, and greater than, 108. (Note that this method of approximation saves time but it is not very accurate if all the answer choices are very close to each other.)