Four Goodness Sake

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

This was quite a challenge and lots of you obviously had a really good go at it. These are from pupils at Moorfield Juniors.

Adam, Abbey and Gemma arrived at $12$ like this:

$4/4=1$ $4-1=3$ $3$x$4=12$

Jimbo and Matt P worked out ways to get $15, 16$ and $17$:

$4/4=1$ $4$x$4-1=15$
$4+4+4+4=16$
$4/4=1$ $4$x$4+1=17$

Numbers $1-9$ were a little harder but you coped very well! Among the correct solutions were these from Emma, Amy, Matthew, Hannah, Steven and Jenny:

  • $4-4=0+4=4-4=0$
  • $4-4=0+4=4/4=1$
  • $4/4=1+1=2$
  • $4*4=16-4=12/4=3$
  • $4-4=0$x$4=0+4=4$
  • $4*4=16+4=20/4=5$
  • $4+4=8/4=2+4=6$
  • $4+4=8-4/4=1 8-1=7$
  • $4+4=8$x$4=32/4=8$
  • $4+4=8 ; 4/4=1+8=9$

Well done for getting these, but could they have been written down in a slightly better way do you think?

Getting $10$ was rather tricky. Pupils at Ysgol Gynradd found a solution but using square roots:

Square root of $4$ + square root of $4+$square root of $4 +4 =10$ .


Published November 2001.