About PiNumpad. Prime Numbers

PiNumpad is a free memory trainer for prime numbers (2, 3, 5, 7, 11, 13, 17, 19...). A prime is an integer greater than 1 divisible only by 1 and itself. This page is the guided learning mode: tap each digit with the path visible, building the motor memory before removing the visual scaffold in Play mode.

Guided digit-by-digit entry. Learn mode shows the path and the digits simultaneously as you tap. Each correct tap highlights the next step; the path is always visible. This bridges the gap between passive study and active recall, letting you build the motor pattern before removing the visual scaffold.

Primes are the atoms of arithmetic. They underpin modern cryptography (RSA encryption, Diffie-Hellman key exchange), appear in physics and biology, and have fascinated mathematicians since antiquity. The sequence is infinite, and its distribution remains deeply mysterious. Tap each digit in order. The path remains visible throughout. When you complete a group, the next group loads automatically. Once the path feels natural in Learn mode, move to Play mode to practice without it.

PiNumpad is designed for cryptography students, competitive memorisers, maths olympiad participants, programmers, and anyone who wants to know the first hundred primes by heart. It runs entirely in the browser with no account, no installation, and no cost. Progress is saved locally using your browser's storage.

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