Excel processes the range (A1:A10) by converting it into an array in memory. This array is what Excel works with to calculate the sum. The distinction is subtle but important: while the range is the ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Who doesn’t love a good math holiday? Most people know about Pi ...

The \(n\)th term for a quadratic sequence has a term that contains \(n^2\). Terms of a quadratic sequence can be worked out in the same way. Write the first five terms of the sequence \(n^2 + 3n - 5\) ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Marguerita is a Certified Financial Planner (CFP), Chartered Retirement Planning Counselor ...

Learn about the origins of the Fibonacci sequence, its relationship with the golden ratio and common misconceptions about its significance in nature and architecture. When you purchase through links ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Some of the most satisfying number puzzles require little mathematical know-how. In fact, cracking the one below calls for thinking that is quite nonmathematical. I don’t know where or when I first ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Today’s topic is Certified Non-Fresh. Sequence risk during retirement—the danger arising from withdrawing assets from a shrinking portfolio—is a familiar subject. For example, my colleagues Amy Arnott ...

The James Bond franchise revolutionized action cinema in the 1960s when it started with 1962’s Dr. No and stands to this day as one of the longest-running film series in history. From almost the very ...

Some strange mathematical sequences are always whole numbers — until they’re not. The puzzling patterns have revealed ties to graph theory and prime numbers, awing mathematicians. Simple, yes, but ...