This book is a must for anyone who enjoys problem solving, word games and brain teasers. Missing Vowels puzzles are excellent for sharp brain maintenance and IQ improvement. Currently one of the ways to prevent/delay Alzheimer's & Parkinson's diseases. Puzzle solving cuts Alzheimer's risk - according to the latest scientific research! Complete the given words on each page missing the letters A, E, I, O, and U. Write the complete word in the grid on the right-hand side. Solutions are provided in reverse on the bottom of each page. The book has 20,000 numbered puzzles. The impact of ordinary activities like listening to the radio, reading newspapers, playing puzzle games, and visiting museumsAfter 4 years, the risk of developing Alzheimers disease was 47 percent lower, on average, for those who did the activities most often than for those who did them least frequently. National Institute on Aging.