How many possible sudoku puzzles are there? In the lottery, what is the chance that two winning balls have consecutive numbers? Who invented Pascal's triangle? (it was not Pascal) Combinatorics, the branch of mathematics concerned with selecting, arranging, and listing or counting collections of objects, works to answer all these questions. Dating back some 3000 years, and initially consisting mainly of the study of permutations and combinations, its scope has broadened to include topics s...

Number theory is the branch of mathematics that is primarily concerned with the counting numbers. Of particular importance are the prime numbers, the 'building blocks' of our number system. The subject is an old one, dating back over two millennia to the ancient Greeks, and for many years has been studied for its intrinsic beauty and elegance, not least because several of its challenges are so easy to state that everyone can understand them, and yet no-one has ever been able to resolve the...

On October 23, 1852, Professor Augustus De Morgan wrote a letter to a colleague, unaware that he was launching one of the most famous mathematical conundrums in history--one that would confound thousands of puzzlers for more than a century. This is the amazing story of how the "map problem" was solved.The problem posed in the letter came from a former student: What is the least possible number of colors needed to fill in any map (real or invented) so that neighboring counties are a...

Can one prove that 1 + 1 = 2? How long is the coastline of Britain? Which US president proved Pythagoras' theorem on right-angled triangles? Who originated the quadratic equation we learned at school? In how many ways can you tile your bathroom? Is there a formula for prime numbers? How often are two winning lottery numbers consecutive? Who was the witch of Agnesi? What is 'the most important theorem in mathematics'? Who scratched mathematical equations on a Dublin bridge? What is...

In 1988 The Mathematical Intelligencer, a quarterly mathematics journal, carried out a poll to find the most beautiful theorem in mathematics. Twenty-four theorems were listed and readers were invited to award each a 'score for beauty'. While there were many worthy competitors, the winner was 'Euler's equation'. In 2004 Physics World carried out a similar poll of 'greatest equations', and found that among physicists Euler's mathematical result came second only to Maxwell'...

“A fine mathematical biography.”—John Allen Paulos, New York Times Book ReviewJust when we thought we knew everything about Lewis Carroll, here comes this “insightful . . . scholarly . . . serious” (John Butcher, American Scientist) biography that will appeal to Alice fans everywhere. Fascinated by the inner life of Charles Lutwidge Dodgson, Robin Wilson, a Carroll scholar and a noted mathematics professor, has produced this revelatory bo...

How many possible sudoku puzzles are there? In the lottery, what is the chance that two winning balls have consecutive numbers? Who invented Pascal's triangle? (it was not Pascal) Combinatorics, the branch of mathematics concerned with selecting, arranging, and listing or counting collections of objects, works to answer all these questions. Dating back some 3000 years, and initially consisting mainly of the study of permutations and combinations, its scope has broadened to include topics s...

Designer Robin Wilson shares tips and tricks to detoxify and beautify your interior spaces and to help you create a more stylish and healthy home.Author Robin Wilson, plagued by allergies and asthma since infancy, has become an expert in Clean Design—creating allergen-reduced home environments that comfort and protect families. Using Wilson’s four principles of design—sustainable, reusable, recyclable, and nontoxic—every room in the home, from attic to basement and...

God Is With Us, originally published in 2016, invites you to explore your longing for God's presence through a study of the lectionary Bible readings for Advent and Christmas. The hope of Advent is the fulfillment of that longing; we await the coming of Jesus as Immanuel, God With Us. Each week's Scriptures call us to praise God as we actively await the coming of Christ and prepare our hearts and lives for his arrival. Through the readings, we hear the invitation to claim...

Fraternal twins, Cari, and Cairo, join their father Calvin on a birdwatching adventure to Snake Mountain. They enjoy being in the wild outdoors as Cari wonders if she will get to see the bird of her dreams.

Are you a man or woman who has been chosen by God andyet you find yourself rejected by man? God’s message to youconcerning the wonderful things you will do for Him have neverbeen clearer, and yet it looks like the opportunity to fulfill that callis thousands of miles away. Experiences of rejection by man andisolation by God have left you wondering if you heard Him right.Sometimes God allows His chosen vessels to experience pain beforepromoti...

Make this year's Advent even more special than usual. Prepare your heart and life for the celebration of God's presence in this season of waiting with God Is With Us, a study of the lectionary Bible readings for Advent and Christmas. By following the lectionary, your study of the Bible and your prayers will be in tune with your pastor's sermon. You'll have a better understanding of the flow of the Scripture readings chosen for the season. Be ready to claim and celebrate the new ho...