This is an excellent text for teaching problem solving, in my opinion the main reason to learn and enjoy mathematics. It seems to me that it goes beyond "school" mathematics, though it fits well with Singapore Math, and could help set kids up for math competitions, such as Math Kangaroo and MOEMS. The book offers a methodological approach to solving problem of many kinds rather than computational skills. The best way to teach complex material is by way of worked examples, and that's how this book goes at it -- very successfully. And fortunately for us teachers, the answers to challenge problems are in the back.