Choose any number between 1 and 20, make simple moves on a clock, and I’ll guess the value of your die! How can it always be found?

Is it really possible to achieve 5 victories in a single trick? After a few manipulations, the magician manages to find the 5 originally chosen cards. Impressive!

At Mathville Elementary School, all 242 students have marbles. Can we be certain that at least two students at the school have the same number of marbles?

Help the city planner design the new look of city hall. Nested circles, areas, radii — there’s plenty to think about!