Problem Solving 101 by Ken Watanabe Summary

Problem Solving 101 teaches practical problem-solving techniques through simple tools like Logic Trees and Hypothesis Pyramids, illustrated via relatable case studies. Originally written for Japanese schoolchildren, it’s designed to help readers break down complex challenges, evaluate solutions, and implement actionable plans. The book uses scenarios like boosting concert attendance for a student band or choosing a bilingual school to demonstrate universal strategies.

This book is ideal for educators, students, professionals, and parents seeking structured problem-solving methods. Consultants and analysts will appreciate its McKinsey-inspired frameworks, while teachers can use it to foster critical thinking in students. Its child-friendly examples make it accessible for ages 12+, though adults find equal value in its simplicity.

With a 4.1/5 Goodreads rating and 4.4/5 Amazon score, Problem Solving 101 is praised for transforming abstract thinking into actionable steps. Reviewers highlight its stress-free readability and real-world applicability, though some suggest additional case studies for deeper exploration. It’s particularly recommended for visual learners due to its charts and diagrams.

Ken Watanabe’s method involves:

• Understanding the problem through root-cause analysis
• Exploring solutions via Logic Trees and Pros/Cons lists
• Testing hypotheses with targeted experiments
• Implementing plans while adapting to feedback

This approach mirrors professional consulting workflows but simplifies them for everyday use.

The Mushroom Lovers—a student band struggling with low concert attendance—demonstrate how to set measurable goals and identify leverage points. Readers learn to use Yes/No Trees to prioritize actions like improving flyer designs or partnering with local cafes, showing how small tactical changes create significant impact.

Key tools include:

• Logic Trees for breaking problems into components
• Hypothesis Pyramids to test assumptions
• Criteria Matrices for evaluating options
• Problem-Solving Design Plans to track progress

These tools are applied to scenarios ranging from career planning to financial budgeting.

While both stem from McKinsey methodologies, Watanabe’s book uses child-friendly examples and visual aids, making it more accessible for beginners. Bulletproof Problem Solving offers deeper corporate case studies but requires prior analytical experience. Watanabe’s approach is preferred for foundational learning and non-business contexts.

Some reviewers note the examples skew toward younger audiences, requiring adults to extrapolate concepts to professional settings. Others request expanded case studies or advanced variations of the tools. Despite this, 89% of Amazon reviewers rate it 4+ stars for its clarity and practicality.

Yes—the John Octopus case study shows how to evaluate career paths using Criteria Matrices. A young aspiring animator weighs factors like cost, skill development, and long-term goals when buying a computer, mirroring real-world trade-offs in career planning. The book’s framework helps users avoid analysis paralysis.

A Yale and Harvard Business School graduate, Watanabe refined his methods during six years at McKinsey & Company. As CEO of education firm Delta Studio, he adapted corporate strategies into teachable systems, blending analytical rigor with accessible storytelling—a balance evident in the book’s structure.

Kiwi’s quest to find a bilingual Brazilian soccer academy demonstrates weighted decision-making. Readers learn to rank criteria (coaching quality, language support, cost) and score options objectively. This approach is applicable to college selections, relocation decisions, or vendor comparisons.

While not quote-centric, key principles include:

• “A problem well-defined is half-solved” (emphasizing root-cause analysis)
• “Test your brightest idea first” (advocating rapid hypothesis testing)
• “Your first solution is rarely your best solution” (promoting iterative refinement)

These mantras reinforce the book’s action-oriented philosophy.