Problem from United We Solve by Tim Erickson, eeps media, copyright 1996.
This is one of the many excellent problems prepared by Tim Erickson. It lends itself particularly to use of manipulatives.
An important point in using the problem is the value of letting the solution steps guide us.
The answer to the problem can, of course, be obtained in a variety of ways. Few of these alternatatives provide sound experience in the problem solving process. In group arrangements it is valuable to compare the various solutions and determine which follow reliable solution processes that will have value in the student's future problem solving experiences. It is not the number of different solutions obtained that is important but rather it is identifying the solution process which will have the greatest future value.
It is not getting the answer that is the important goal. This can always be done. It is how the problem was solved that is important. This develops the foundation for problem solving in general. Problem solving is a process.