In a comment Nick points out that using the 4 basic operations to combine 4 numbers to make 24 can be tricky when the only solution is of the form

a/(b – c/d), for a suitable choice of a, b, c, and d!

This blog has gotten repeated hits for 3,3,8,8, which has a solution of that form, and 1,3,5,7 (apparently making 21, not 24), with a solution of the same form.

Can you come up with more? I find that most neat ones have easier solutions. 2,3,8,17 can be combined Nick-style to make 3/[(17/8)-2] , a nifty 24, but why bother when 17+8+2-3 accomplishes the same thing?

2,4,6,13 doesn’t work. 4/[(13/6) – 2] looks nice, but why not the much simpler 2(13 – 4) + 6 ? Are there any others?

By the way, Nick runs a site with grown up puzzles which I find quite challenging and enjoyable. To take a look, click

Nick’s Mathematical Puzzles