How Smart Are You? Reasoning & Problem-solving tests and stimulates critical thinking and problem-solving skills. It is mainly a supplementary educational book but can also be used recreationally - a very handy, travel-friendly product. Although primarily geared towards upper primary students (10 years and over), lower secondary students and adults will find the activities interesting and stimulating. The book comprises 25 smart tests with 20 items each. The tests are progressively challenging and cater to those at varying learning levels.