Some Babylonian trick
4552
Choice of $q$ in Baby Rudin's Example 1.1
97044
What is the name of this effect, and what is a good way to replicate it?
35864
Playing with numbers form $1$ to $n^2$ in an $n\times n$ grid
21598
A game of guessing a chosen number
26607
The idea behind the sum of powers of 2
157334
A valid floor function trick?
121880
How to show that $|D_{2n}| = 2n$ via the presentation?
80754
A slight modification in Chinese Remainder Theorem
90820
Is it possible to 'split' coin flipping 3 ways?
42462
Use a linear approximation to estimate the number $64.07^{2/3}$
65335
A "binomial" generalization of harmonic numbers
5187
An analogue of Hensel's lifting for Fibonacci numbers
28645
Alice and Bob play the determinant game
142300
Winding number (demonstration)
35571
Euler Rotations in Ordinary Space
134440
An unexpected application of non-trivial combinatorics
2786
The staircase paradox, or why $\pi\ne4$