The Number Sense Handbook

Number Sense is not a test of how fast you can do arithmetic. It is a test of how many problems you can solve without doing arithmetic at all.

The Number Sense Handbook collects 295 mental math shortcuts and works every one of them out step by step. Each trick follows the same four-part format: an explanation of why it works, the formula to memorize, a worked example, and a practice problem with a full answer. A priority key marks every trick as must-know, worth learning, hard-question territory, or skippable under time pressure, so students know where to spend their study time.

Inside: 295 tricks across 13 sections, from multiplying by 11 to definite integrals. A Memorization Vault of squares, cubes, factorials and trig values worth knowing cold. Two full practice tests of 80 problems each with scored answer keys. A complete answer key and an alphabetical topic index.

Smyan Ramnath wrote this book at 14, while competing in TMSCA Number Sense at the regional and state levels. It grew out of the notes he made preparing for his own meets.