Math & statistics, from the ground up

So… WHY does this count?

Math and statistics explained the way they should have been the first time: where it shows up, why it matters, then what it is.

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  • Daily Shorts at 4 PM ET
  • Nightly long-form lessons
  • Free, always
Hi, Sigma here!
Sigma, the tutor: a friendly cartoon in a teal cardigan and round glasses, holding a pointer

Meet the Family

One family, one Greek letter each

Sigma hosts every video. Each subject gets a co-host from his family who brings it into real life.

  • Sigma

    Sigma Σ

    The tutor · every series

    “So… WHY does this count?”

  • Delta, in a coral track jacket with a stopwatch

    Delta Δ

    Calculus · Sigma's girlfriend

    “How fast is it changing right now?”

  • Theta, in a yellow hoodie and backwards cap with a skateboard

    Theta θ

    Trigonometry · best friend

    “It's all about the angle.”

  • Grandma Mu, in a lilac shawl with knitting needles in her bun

    Grandma Mu μ

    Statistics · grandmother

    “On average, dear, I'm always right.”

  • Epsilon, Sigma's little brother, in a striped tee with a backpack

    Epsilon ε

    The Bridge · little brother

    “But WHY?”

  • Pi, a chef in a raspberry apron holding a pie

    Pi π

    Probability · cousin & chef

    “Wanna bet? …Let's count it first.”

  • Lambda, the grey tabby family cat

    Lambda λ

    Linear Algebra · the cat

    “…meow.”

But WHY?
Epsilon asking why

How Sigma teaches

Where → Why → What

Most classes start with the formula. We finish with it.

  1. 1

    Where

    Start in real life: the track, the bakery, the skate ramp, a medical test. A co-host shows where the idea is already in your day.

  2. 2

    Why

    Epsilon asks “But WHY?” and we answer with a picture you can't forget, not a rule to memorise.

  3. 3

    What

    Only then the formula, once it already makes sense, with every number checked.

Series

Pick where you want to start

Ordered from high school to college, easy to hard. New to it all? Start with The Bridge.

  • The Bridge

    From arithmetic to algebra. Fractions, negatives, variables, the stuff everything else is built on.

    with Epsilon

  • Statistics

    Averages, spread, samples and bias, told through cookie batches and knitting rows.

    with Grandma Mu

  • Probability

    Dice, spinners and pie slices. Count the outcomes before you bet the cookies.

    with Pi

  • Trigonometry

    Ramps, shadows and throws. Sine and cosine stop being mysterious.

    with Theta

  • Calculus

    Rates and totals with a stopwatch: how fast, and how much, right now.

    with Delta

  • Linear Algebra

    Vectors, matrices and eigen-things, via a cat who pushes everything off the table.

    with Lambda

New every day

A lesson every morning. A Short every afternoon.

A new long-form lesson lands every morning, and a bite-size Short every day at 4 PM ET.

See the latest videos
The whole Sigma Explains family standing in a row