How would you use the Major System to memorize a phone number or a bank PIN?

Chunk it into pairs, convert to pegs, and link them into a mini-scene tied to the person or account.

A number like 079 412 8856 → 07 · 94 · 12 · 88 · 56 → sack, bear, tuna, fife, leech. Picture the scene anchored to whose number it is, following the pegs in order: a burlap sack bursts open and a bear climbs out, kicks a tuna, then plays a fife for a leech.

The story: a burlap sack splits open, a bear clambers out, kicks a tuna, then plays a fife to a waiting leech.

This turns an abstract string into one recallable image — far more reliable than rote digits, and it survives interruptions (unlike "just say it over and over"). For a PIN, keep the scene private and never write the digits down; the mental image is the only stored copy.

Tip: Anchor the scene to context (the friend's face, the card's colour) so the right number surfaces with the right cue.