Sept. 12-13 -- Stacks of 100 Mathlete Dollars

We kicked off the new year with a lesson teaching the children how to find the factor pairs of 100. Of course, we didn't use the word "factor," but we had the children make piles of one hundred Mathlete Dollars in a single denomization.

First, we had them look at using the One Dollar denomination. Of course, this would have taken forever, counting out 1 to 100 by consecutive integers. They were excited to learn that Albert Einstein is on the One Dollar Mathlete note.

Second, we looked at the Five Dollar denomination and they used their fingers to count to 20. They seemed intrigued that this process went five times as fast. Many of the children can count by fives to 100 easily and others are just feeling the rhythm of number. Archimedes is on the Five Dollar Mathlete note. He was a third century BC Greek mathematician and engineer. He developed the general theory of levers and invented the catapult. Archimedes also found the relationship between the radius of the circle to the circumference of a circle. We will study all of his theories in Mathletes.

NOTE: You will see that I allow them, even encourage them, to use their fingers and if applicable, their toes. There is no surprise the the Base Ten number system emerged as the standard. Developmentally, they will grow out of the need to use their fingers to count. However, I still teach high schoolers to use their fingers to count by powers of two; the numbers of fingers indicating the power. For example, 2,4,8,16,32 with five fingers up you know this is 2 to the 5th power.  

Third, we looked at the Ten Dollar denomination and they liked this the best. Twice as fast as fives and ten times faster than Ones. We didn't talk much about Blaise Pascal who is on the Ten note but we will. Pascal was a 17th Century French mathematician who invented the first mechanical calculator and developed theories of probability still used today.

Fourth, we looked at the Twenty Dollar denomination and the children loved the simplicity of counting by twos: 2,4,6,8 and 10; but in reality 20, 40, 60, 80, 100. Plato the Fifth Century BC Greek Philosopher and mathematician, will be studied during the year.

Fifth, we looked at the Fifty Dollar denomination on which Johannes Kepler is the face. Kepler will help us introduce the mathematics of the planets. Of course, counting by 50 takes no time at all.

Sixth, we looked at the One Hundred Dollar denomination. No counting required. Incidentally, Pythagoras is the face of the 100 and will be studied later in the year.

Some of the children asked about a Twenty-Five Dollar, Four Dollar or Two Dollar denomination. These are the types of questions that create mathematicians. One girl even inquired about a Two and a Half Dollar note. It is going to be a fun year.

I had the children count by 100s by making stacks of 100 using 5s, 10s, 20s, 50s, and of course, 100s. In some classes we were able to total the 100s into groups of 1000.

PRACTICE: 1. Please have the children count by these denominations to 100 and go beyond if they desire.      

2. Please have them adopt a few favorite numbers to share in class. 

I love when children adopt a number and can talk about what is special about it. They usually focus on their age or their age coming up. Of course, they think of age in years. This year we will explore age in months, weeks, etc. This is more fun. Imagine answering the most basic question, "How Old Are You?" with "65, in months."

If they are able to share what they did during the week, they will get Mathlete Dollars during the next class that they can keep until the end of the year. The work during the week is not mandatory from my perspective. I do not want them to think of Mathletes as homework which they dread. I want them to want to do the work. We use positive peer pressure to encourage kids to ask to do their Mathlete work every week.

Every child in Mathletes at the end of the year gets some toy or book on the last class. They turn their dollars in for the gift. The child with the most Mathlete money chooses first in the group, the child with the next most chooses second and so on. The toys range from Iphone (usually one electronic devise every year), to hockey sticks, soccer balls, to water shooters, side walk chalk, books, puzzles, etc. They are usually the latter type.  

Have fun exploring math with your children.