Brain teaser: Can you crack the code and find the missing number in the triangle? A popular online math puzzle involves finding a missing number in triangles by using a simple addition rule ...

CAN you crack this code? Check out mathematical quizmaster Adam Spencer’s new Christmas riddle. Adam Spencer less than 2 min read December 20, 2017 - 3:12PM ...

It's this complexity that keeps people coming back for more, eager to crack the code and prove they have what it takes to solve even the most puzzling problems.

With titles like “99% will fail” or “Can you solve this?”, these challenges are designed to test our reasoning, comprehension, and sometimes our patience.

With cryptography vital to the war effort, crossword solvers were seen as possessing the analytical and lateral-thinking skills needed to help crack these codes.