Pity Four Fours

 “How d’you make the number 7, just using the number 4 four times?”

 (One possible answer is        )

You have probably been asked something similar at some time during your mathematical life.

In fact, there are lots of other ways to make 7, including    and  

This gives you a couple of nice Sneaky Tricks that may be new to you:

            4! = 4 x 3 x 2 x 1 = 24           and                   

The Problem:

Well here’s the full Problem – all grown-up and really quite tricky in places:

“How d’you make all the numbers from 1 to 20, just using the number 4 four times?”

Open the File as a Word Document


Send site mail to admin@1000problems.org  or personal comments direct to sdakeyne@psc.ac.uk with questions or comments about this web site.
Last modified: June 18, 2007