New posts in Recreational Mathematics

Can there be a magic square with equal diagonal sums different from equal row and column sums?

Product of 2-digit numbers

What is the value of $\arctan \left(\frac xy\right) +\arctan \left(\frac yx\right)?$

What's the closest approximation to $\pi$ using the digits $0-9$ only once?

Fitting a piece of furniture through a corridor

New Year Maths 2018: $\color{green}{\binom ab+\binom bc+\binom cd}+\color{orange}{\binom de+\binom ef+\binom fg+\binom gh}=\color{red}{2018}$

Guessing a number between $1$ and $100$ with 10 distinct questions and 9 honest answers

Function taking on all values thrice

Find the length of a diagonal in an inscribed (non-regular) hexagon

Mathematical coincidences concerning the numbers $\pi$, $e$ and $163$