This was a situation in developmental Math class when students learn the skill of adding and subtracting integers by discovery method. I gave each student four colored strings: one long and one short red yarn to represent negative values, one long and one short green yarn to represent positive values. I allowed them to manipulate the yarn through addition and subtraction and let them discover first, the result, and then let them generalize the rules involved in each operation. It took them only a short time to understand the procedures than following the written procedures in the book. Discovery method is truly a "learning by doing" technique in understanding abstracts. It also proved effective to visual learners.
