IDEA #8

People are terrible at fractions

cartoon

Bad maths can lead to some ridiculously poor choices.

What you need to know

Special offer time! You’re trying to get your supermarket shopping done in the fastest time possible. Nearly done, you just need to pick up a pack of breakfast cereal and are confronted with two offers for nearly identical products:

  • ‘Extra value time! Get 33 per cent extra cereal – free!’
  • ‘Discount time! We’ve knocked 33 per cent off our price!’

There’s no difference, right? I’m afraid there’s quite a major one. Do the maths and you’ll find that the second offer is the much better deal; you’d need 50 per cent more cereal ...

Get 101 Business Ideas That Will Change the Way You Work now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.