Read one problem per week. Spend Saturday reading the history, Sunday attempting a solution, Monday studying Dörrie’s method. After 100 weeks, you will have traveled through 2,000 years of mathematical discovery.

| Book | Focus | Difficulty | |------|-------|------------| | Problem-Solving Strategies (Engel) | Olympiad problems | Intermediate | | The Penguin Dictionary of Curious and Interesting Numbers (Wells) | Number theory lore | Easy | | What Is Mathematics? (Courant & Robbins) | Concepts + problems | Intermediate | | Unsolved Problems in Number Theory (Guy) | Open problems | Advanced | ✅ Obtain the Dover paperback (ISBN 978-0486613482) – it is cheap, portable, and legally clear. ✅ If cost or shipping is an issue, borrow from Internet Archive (digitized scan available). ❌ Avoid shady PDF sites – many scans are missing pages or have illegible equations.

The problems are “elementary” only in their statement – not in difficulty. Many stumped the world’s best mathematicians for centuries (e.g., Fermat’s Last Theorem for n=3, the Basel problem, the transcendence of π). 2. How to Find a Legitimate PDF Due to copyright restrictions, I cannot provide a direct PDF. However, the book is in the public domain in many countries (original German: 1932; English translation: 1965, Dover reprint). Here are your best legal options: