The best problems selected from over 25 years of the Problem of the Week at Macalester College.

A meditation on the beauty and meaning of numbers, exploring mathematical equations, describing some of the mathematical discoveries of the past millennia, and pondering philosophical questions about the relation of numbers to the universe.

'I am blown away by the level of detail Phil Cavell brings to his work.' – Elinor Barker MBE, multiple world champion and Olympic gold medallist 'The Midlife Cyclist is a triumph' – Cycling Plus 'An amazing accomplishment... a simple-to-understand précis of your midlife as a cyclist – you won't want to put it down.' – Phil Liggett, TV cycling commentator 'Phil is eminently qualified to write The Midlife Cyclist. Well, he is certainly old enough.' – Fabian Cancellara, Tour de France rider and two-time Olympic champion Renowned cycling biomechanics pioneer, Phil Cavell, explores the growing trend of middle-aged and older cyclists seeking to achieve high-level performance. Using contributions from leading coaches, ex-professionals and pro-team doctors, he produces the ultimate manifesto for mature riders who want to stay healthy, avoid injury – and maximise their achievement levels. Time's arrow traditionally plots an incremental path into declining strength and speed for all of us. But we are different to every other generation of cyclists in human history. An ever-growing number of us are determined to scale the highest peaks of elite physical fitness into middle-age and beyond. Can the emerging medical and scientific research help us achieve the holy triumvirate of speed and health with age? The Midlife Cyclist offers a gold standard road-map for the mature cyclist who aims to train, perform and even race at the highest possible level.

"Martijn Doolaard traded in the convenience of a car and the distractions of daily life for a cross-continental cycling journey: a biped adventure from Amsterdam to Singapore. Leaving behind repetitive routines, One Year on a Bike indulges in slow travel, the subtlety of a gradually changing landscape, and the lessons learned through travelling. Venturing through Eastern European fields of yellow rapeseed to the intimate hosting culture in Iran, One Year on a Bike is a vivid chronicle of what can happen when the norm is pointedly replaced by exceptional self-discoveries and beautiful sceneries. Doolaard shares the gear and knowledge that made his trip possible." -- Provided by publisher.

Can Marcel make the ride of his life? Marcel loves riding his bicycle, whether he's racing through the streets of his small town in France or making bread deliveries for his parents' bakery. He dreams of someday competing in the Tour de France, the greatest bicycle race. But ever since Germany's occupation of France began two years ago, in 1940, the race has been canceled. Now there are soldiers everywhere, interrupting Marcel's rides with checkpoints and questioning.Then Marcel learns two big secrets, and he realizes there are worse things about the war than a canceled race. When he later discovers that his friend's entire family is in imminent danger, Marcel knows he can help -- but it will involve taking a risky bicycle ride to pass along covert information. And when nothing ends up going according to plan, it's up to him to keep pedaling and think quickly... because his friend, her family, and his own future hang in the balance.

In the summer of 2010, brothers-in-law Marty and Jim embark on a cycling trip along the Great Allegheny Passage and C&O Canal, a 335-mile trek from their home in Pittsburgh, Pennsylvania to Jim's boyhood home in Washington, DC. Chance encounters with colorful local characters and other surprising escapades during five days on the trail make for nonstop laughs. As they travel through forests and along winding rivers, they experience the breathtaking scenery of western Pennsylvania, Maryland and West Virginia, exploring early American history while learning more about each other as well as themselves. This true story is for adventurers and cyclists as well as couch potatoes looking for a lighthearted take on friendship and some hilarious fun.

Robert Penn has saddled up nearly every day of his adult life. In his late twenties, he pedaled 25,000 miles around the world. Today he rides to get to work, sometimes for work, to bathe in air and sunshine, to travel, to go shopping, to stay sane, and to skip bath time with his kids. He's no Sunday pedal pusher. So when the time came for a new bike, he decided to pull out all the stops. He would build his dream bike, the bike he would ride for the rest of his life; a customized machine that reflects the joy of cycling. It's All About the Bike follows Penn's journey, but this book is more than the story of his hunt for two-wheel perfection. En route, Penn brilliantly explores the culture, science, and history of the bicycle. From artisanal frame shops in the United Kingdom to California, where he finds the perfect wheels, via Portland, Milan, and points in between, his trek follows the serpentine path of our love affair with cycling. It explains why we ride. It's All About the Bike is, like Penn's dream bike, a tale greater than the sum of its parts. An enthusiastic and charming tour guide, Penn uses each component of the bike as a starting point for illuminating excursions into the rich history of cycling. Just like a long ride on a lovely day, It's All About the Bike is pure joy- enriching, exhilarating, and unforgettable.