Marshall’s Weblog

Embiggen Your Mind

Marshall’s Weblog header image 2

Four Fours

December 6th, 2006 · 3 Comments

I just found out about a little math game called Four Fours. Basically what you try to do is try to represent integers using only the number 4 and a few common mathematical operators, for example:

0 = 4 - 4 + 4 - 4
1 = ( 4 + 4 ) / ( 4 + 4 )
2 = ( 4 * 4 ) / ( 4 + 4 )

There are also solvers out there in C# and also in Python.

Tags: Math · Programming

3 responses so far ↓

  • 1 donnie // Dec 11, 2006 at 9:21 am

    3 = ( 4 * 4 - 4 ) / 4 -or- (4 + 4 + 4) / 4
    4 = 4 * (4 - 4) + 4
    5 = ( 4 * 4 + 4 ) / 4
    6 = 4 + (4 + 4) / 4
    7 = 4 + 4 - (4 / 4)

    does this count: 7 = ( 44 / 4 ) - 4 ?
    8 = 4 * ( 4 + 4 / 4 )

    man, that’s pretty tough! If you can use only +,-,*, and / then the biggest number you can make is 4*4*4*4 = 256 and I don’t see how you could make any number between 4*4*(4+4)=96 and 256…

  • 2 Marshall // Dec 11, 2006 at 9:53 am

    Yes, 44 is valid, as is 4.4 if you want or .44. You can also use the sqrt(), !, and ^ operators!

  • 3 Gabrielle // May 30, 2007 at 2:20 pm

    could you go threw 100 please

Leave a Comment