Spark & Anvil Privacy
A warm little theatre stage with a small curtain, a giant wooden abacus and building blocks, a tween performing a clever maths trick for friends

The setlist

Do maths people ask you to do again.

A magician can name the day of the week you were born on — in their head, in a second. These are real number tricks (place value and clock-style “mod” maths), not gimmicks. Learn the secret, then perform. The unit of progress here isn’t a streak — it’s a show you gave someone.

Opener Any-Day A fresh date every day — guess the weekday, then learn the Doomsday method that gets it every time. The show Show Mode Hand someone your phone. They enter a birthday or hide a digit; you take a bow. Nothing is saved or sent. The secrets Three real tricks ×11 by adding the middle · squares ending in 5 in one step · casting-out-nines to find a missing digit. Practise the first two in MentalForge’s Trick lab.

Rehearse, then perform

The tricks are self-working — the maths does the magic — but a smooth performer has done the mental adding a hundred times. Drill the arithmetic at MentalForge, then come back here and put on a show.

Honest promise: this makes practice fun and gives you something to show off — it isn’t a claim to make you a genius. On-device, no account, no timer, no streak, nothing leaves your phone.

Cast, stories & more
ShowMath mascot

Meet the cast — the characters who teach this

Each one stands for an idea you’ll practice. Tap a character to read their illustrated story and hear their audio drama.

Ensemble stories — the cast together

Explore all the stories →

What next? Pick a door

Chosen from what this app is about. What you open is remembered on this device only.