Math / History : Prime Numbers & Eratosthenes

Our current Miquon labsheets are exploring the concepts of prime numbers and factors. The use of our cuisenaire rods had made it very easy for the boys to visualize these.

For enrichment, we read from an entertaining Math book called The Further Adventures of Penrose the Mathematical Cat by Theoni Pappas. There is a chapter in the book where Penrose the cat illustrated the concept of prime numbers and factors by arranging square tiles and explained how the name "composite numbers" was derived.

The chapter ends with a challenge to use 'The Sieve of Eratosthenes' to find the prime numbers from 1 to 100. This is my boys' untidy :-P but mathematically correct working:


In the process of crossing out the composite numbers to find the prime numbers (that are circled), we talked about even numbers, multiples of a number and number divisibility.

Since Eratosthenes happened to be a Greek mathematician who lived from 275 B.C. to 194 B.C. (the Greek era we are currently at for our History study), we decided to read more about him.

We read a beautifully written picture book, The Librarian Who Measured the Earth by Kathryn Lasky. The language used is very rich. The mathematical concepts discussed are a little beyond the boys now. (It covers a fair bit of geometry.) Nevertheless, my boys found the book engaging because it gives a very vivid description of ancient Greek culture.

They were thrilled to see the familiar Greek pottery in the illustrations. (We are half way making our Greek jars at the moment. Watch out for my post on that...)

Eratosthenes was described as being a child who loved and dared to ask questions.
B: Hey, isn't he just like Socrates?! (See my past post on Socrates)
Mama: Yes. :-)

We will surely be revisiting this book.


Visit Rumphius Mathematics Webpage or History Webpage to find out more about how we approach Mathematics or History in our homeschool.