Focus on Math

Helping children become mathematicians!

Free On-Line Graphing Calculator June 21, 2012

 For those doing secondary mathematics, this free on-line graphing calculator may be of interest. For those who have iPads, there are free graphing calculator apps available, but it is nice to have one available on a home or laptop computer as well. Besides being helpful for completing homework assignments, the graphing calculator is a great learning tool as well. For example, by comparing the graphs of particular equations [such as those for x^2, x^2 + 3 and (x + 3)^2] one can gain an understanding of how a graph is translated on the Cartesian plane.

Click here for the link to the on-line graphing calculator.

Mathematically yours,


Bean Thirteen — a Lesson in “Fair-Sharing” June 15, 2012

One of my recent purchases was the delightful book Bean Thirteen by Matthew McElligott. The story tells the tale of Ralph and Flora, two bugs who were picking beans for dinner. Ralph warns Flora not to pick the thirteenth been (as it is unlucky!) but as Flora does not agree with Ralph, she goes ahead and picks bean the thirteenth bean. Then dilemma begins. If they split the beans between them, bean 13 is left over. If they invite one, two, or four friends over to share the beans with, bean 13 is still left over. (And there was real trouble when they only tried to invite 3 friends over!) The final solution for the problem is a real-life example of problem solving at its best. Bean Thirteen is a great book to use for developing the concept of division for K-3 students.

After reading the book to my two grade 2 classes, I had them do an activity based on the book. Students each counted out 18 bingo chips to represent beans, and then they were asked to share them on “plates” for different numbers of friends. I provided cut up pieces of construction paper to represent the plates, and the students shared out the beans equally on the plates. (We called this “fair-sharing”.) Beside the number of plates (or number friends sharing) listed on the recording sheet, students wrote down the number of beans on each plate and the number of beans (if any) left over.

Because of the concrete nature of the activity, everyone was able to be successful. Early finishers were allowed to take a different number of “starting” beans and explore what would happen when that number of beans was shared.

If your school library does not have a copy of this book, ask your librarian to order one in. It is well worth having.

Mathematically yours,

Download the full-sized activity sheet here.