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 you a genuine mathematical formula that works for any date…
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: what equations are, how they work, types of equations, and…
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 imaginary numbers to quaternions, are built from a few simple…
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 ideas or verify they're correct. I walk you through propositions,…
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 produces primes for the first 40 values, then fails spectacularly.…
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.' It felt like magic. I'll teach you the crisscross method…
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 needed. I explain the method step by step, prove why…
Two Interesting Math Problems
Two math problems that'll make you think. First: find the smallest autobiographical number where each digit tells you how many times a digit appears. Second: a classic puzzle involving a…
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 constant speed. What path does the fox follow? I present…
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 few points. At no points whatsoever. I walk through the…
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: from simple repetition and spaced practice to visualization techniques and…
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 made freely available online. This curated list covers single-variable calculus,…