infinite series

How to sum an infinite series using chocolate.
James Maynard has won a field medal for his work in number theory. He told us how he went from a fascination with numbers as a young child to making spectacular contributions to number theory.
Approximating a function with a divergent series.
If you ignore exponentially small terms they can come back to bite you.
How a question about rainbows led to an entire field of mathematics.
Scientists have calculated the decimal digits of the number pi to a record 62.8 trillion places.
This problem about an infinite sum has a surprising answer.
How to write a sum that's infinitely long.
What is 1-1+1-1+1-1+...? How infinite sums challenge our notion of arithmetic.
What do you get when you add up all the natural numbers 1+2+3+4+ ... ? Not -1/12! We explore a strange result that has been making the rounds recently.
The number pi can be expressed beautifully in terms of infinite sums. For practical purposes though, these sums are rather disappointing: they converge slowly, so you need to sum a large number of terms to get accurate estimates of pi. Here's a clever way to make them converge faster.