Multiplication Magic!
by Carol Wells
The fourth-grade class has spent a good deal of time studying multiplication. In this lesson the students investigated multiplication from a different approach - through a geometric investigation of rectangular arrays. I did this to help the children build their concept development of multiplication.
The first part of the lesson was to introduce rectangular arrays. The children worked in groups of three and were assigned the task of finding all the different rectangles there were for each of the numbers 1 to 25. The groups then shared the different methods they found for constructing the arrays with the class.
We then answered some questions as a group, discussing the patterns that we found and I also introduced some new vocabulary.
Following our group discussion I introduced a way to transfer their rectangles numerically to form a multiplication chart. Further explorations of the multiplication chart were done so that the students could exam visual patterns on the chart. The children enjoyed the exploration and through the activity were able to develop a familiarity with multiples and deepen their understanding of the concept of multiplication.
