Defines addend, average, mean and median and their connections; demonstrates left-to-right row addition to find sums much more quickly; how to estimate sums by inspection; how to round numbers up or down to a specific place value for quicker estimations; how to add large sequences of natural numbers efficiently; how to add large sequences of natural numbers using the mean and median. Generally, ways to approach addition and multiplication calculations when there is no calculator available – techniques that are particularly useful on standardized tests, such as the SAT and ACT, or generally, when time is severely limited. 45 problems solved in detail, with explanations. Includes a topic-specific glossary and index.