Numbers are hard. Shapes are easy.

Try to picture the number 7. Now try to picture a flag on a pole.

The flag was easier, wasn't it? Digits are abstract, and memory doesn't have much to grip on them. So the trick is to swap each digit for an object that looks like it.

This week's trip

Learn these ten. Most of them are obvious once you see them:

• 0 a ball
• 1 a candle
• 2 a swan
• 3 a pair of handcuffs, or lips on their side
• 4 a sailboat
• 5 a hook
• 6 a golf club
• 7 a flag or a boomerang
• 8 a snowman
• 9 a balloon on a string

Read through once and look away. You'll probably get most of them on the first try.

Now use them

Say a door code is 4 8 2 7. Make it a tiny film:

A sailboat crashes into a snowman. The snowman's head rolls away and a swan catches it, then flies off carrying a flag.

Four digits became one short scene, and it's much harder to mix up the order of a story than the order of a number.

Where this goes next

Ten shapes are enough for PINs and short numbers. For longer ones, like dates or phone numbers, memory athletes use a bigger code that turns pairs of digits into words. That's a trip for another week.

For now, take one number you always have to look up and turn it into a scene. Run the film twice today and once tomorrow, then see if you still need to look it up.