Obviously this task requires some understanding of addition, subtraction, the symbols and the structure of equations. A range of solutions can be found. Encourage the more able to find all the solutions and convince others that they have them all.
<P>
Ask children to examine the solutions they have found and discuss observations. For example: The numbers are all even. Some are the reverse (2+4 is like 4+2). Some are the inverse (2+4=6 and 6-2=4).
<P>
The task is easily extended through "What if" questions. What if the numbers can be used twice? What if a 1 or a 0 is included? 
<P>