
Problem-Solving Strategies is a unique collection of competition problems from over twenty major national and international mathematical competitions for high school students. The discussion of problem-solving strategies is extensive. It is written for trainers and participants of contests of all levels up to the highest level: IMO, Tournament of the Towns, and the noncalculus parts of the Putnam competition. It will appeal to high school teachers conducting a mathematics club who need a range of simple to complex problems and to those instructors wishing to pose a "problem of the week," "problem of the month," and "research problem of the year" to their students, thus bringing a creative atmosphere into their classrooms with continuous discussions of mathematical problems. This volume is a must-have for instructors wishing to enrich their teaching with some interesting nonroutine problems and for individuals who are just interested in solving difficult and challenging problems.
It depends on their age and skill level. It goes without saying that younger kids need more guidance if they aren't extremely motivated.
This is worth looking into: https://artofproblemsolving.com, it's kind of the go-to website for the competitive math community. There are a lot of free high-quality resources on the wiki, and they sell courses and books.
A couple classic books: https://www.amazon.com/Art-Craft-Problem-Solving-3E/dp/11194... https://www.amazon.com/Problem-Solving-Strategies-Problem-Bo...
And obviously, competition problems! For example, this is the AMC: https://amc-reg.maa.org/default.aspx; competition websites usually have an archive of past editions freely available. Studying past problems is the meat and potatoes of actual competition training. Make sure they are age appropriate, because the difficulty level ramps up VERY fast.
The process of writing will hopefully help you:
- build awareness of when your arguments are not airtight or when you make false assumptions
- modularize your thinking
- become more fluent with logical "vocabulary"
As for books, my personal favorites were Problem Solving Strategies (Engel) and Art and Craft of Problem Solving (Zeitz). They're both really approachable, have plenty of examples, and will give you a different perspective on what math can be about.1. The foundations of mathematics by Stewart and Tall
2. Problem Solving Strategies by Arthur Engels
3. Journey into Mathematics by Rotman
4. Concrete Mathematics by Knuth et al.
[1]https://www.google.com/books/edition/Problem_Solving_Strateg...