Find the Day of a Date using this Calendar Formula
You can figure out what day of the week any date falls on. No calendar needed. Just arithmetic. I'll teach…
Study Notes
Equations: A Basic Introduction
Equations are the reason we can solve problems in seconds that would take hours of guesswork. I cover the basics:…
Numbers – The Basic Introduction
Numbers are the alphabet of mathematics. But here's what most people never learn: all the complex numbers you encounter, from…
Mathematical Logic – The basic introduction
Logic is the grammar of mathematics. You can have brilliant mathematical intuition, but without logical precision, you can't communicate your…
Fermat Numbers (Important Theorems & Examples)
Fermat was convinced he'd found an infinite source of primes. He was wrong. His formula n^2 + n + 41…
Vedic Multiplication: Do you multiply this way!
Before college, I multiplied numbers the boring way. Then I discovered Vedic multiplication in a Hindi magazine called 'Bhaskar Bhoomi.'…
Russian Peasant Multiplication: The Ancient Method That Uses Only Doubling and Halving
Russian Peasant Multiplication is an ancient technique that multiplies any two numbers using only doubling and halving. No multiplication tables…
Fox-Rabbit Chase Problem [Solution & Math Proof]
Pursuit problems are some of the most elegant challenges in classical mechanics. A fox chases a rabbit, both moving at…
Everywhere Continuous Non-differentiable Function
Weierstrass shocked the mathematical world in 1872 by constructing a function that's continuous everywhere but differentiable nowhere. Not at a…
10 Memory Methods to Revise and Remember Better
Memory isn't fixed. You can train it. I've compiled ten practical methods to improve how you retain and recall information:…
Free Online Calculus Text Books
I've spent years collecting free calculus textbooks. Not scanned copies with missing pages. Real textbooks that professors and universities have…
Dedekind’s Theory of Real Numbers
Most math students use real numbers without ever understanding how they're constructed. Dedekind solved this with his theory of cuts.…