Sunday, May 25, 2014

Doing Math

Nets for Geometric Models

Inspired by the book Adventures Among the Toroids by B.M. Stewart, I searched for a polyhedron net with "holes."  What I found was a 3 dimensional flexagon, which is hinged together at common sides.  As opposed to typical flexagons, this one is not a static figure, rather it is a kaleidocycle that can move and transform into different shapes.  The type of kaleidocycle I made is a type of hexaflexagon, which displays six triangular faces at the same time and can be transformed to display a different set of six triangles.  I am posting pictures of some of the steps I took in creating my kaleidocycle.


Here is the link for the instructions which I used to make my 3D hexaflexagon.:
3D Hexaflexagon

My hexaflexagon:






This kaleidocycle inverts to display a different pattern on the other side.  This was a really interesting and fun activity that I hope to bring to my students someday.  I could incorporate lessons about vertices, edges, faces, polygons, perimeter, area, and volume.
 
As I was exploring on the Internet, I came across this great math lesson for exploring area, perimeter, and volume, using polyhedra and flexagons.  This lesson aligns with 5th grade Common Core State Standards. 
Understanding Polygons and Polyhedrons Using Flexagons

Here is a real world example of a polyhedron with a hole. It is a little distorted, but it is a lamp.  This is different than a flexagon since its shape is static in nature.  It does not change but it was created with a hole in the middle, staying true to the properties of the polygon.

Sunday, May 18, 2014

Nature, History, Explanation, and Doing of Math

Al-Khwarizmi made this week's post really easy (although time consuming) due to the rich contributions of his work.  This brilliant mathematician allows me to touch upon a little of everything for this course -
  • Explaining math (the origin of our number system)
  • The Nature of Mathematics (linking geometry and algebra)
  • The History of Mathematics (the role al-Khwarizmi played at the House of Wisdom)
  • Doing Math (creating a tiling inspired by the Islamic tilings)
This is so cool! I found this image as I was researching our most recent mathematician, al-Khwarizmi.  While the image is what caught my eye, as I dug deeper, I found out that al-Khwarizmi actually invented our numeral system by determining the number of angles formed by line segments. This is one of the most basic representations of how algebra and geometry are linked.  Rather than being English numbers, these are actually considered to be Hindu-Arabic numbers. 
Al-Khwarizmi is known as the Father of Algebra.  At the end of the forward for his book, the Compendious Book on Calculation by Completion and Balancing, al-Khwarizmi gives credit to God for encouraging him to persevere through difficult times to ultimately write such a concise and useful work of mathematics.  The word "algebra" is a Latin derivative the Arabic word Al-jabr, which came from his Compendious Book.  Attached is a link to a short and easy to follow description of what algebra means: The Origin of the Word Algebra  .

We can find further evidence of Al-Khwarizmi linking algebra and geometry through his use of geometric shapes (squares and units) to create algebraic expressions, as we saw when using algebra tiles in class on Thursday.  Here is an example of a problem I did using the virtual algebra link  Virtual Algebra tiles provided in class:


As one of the original contributors to the the House of Wisdom (a library, translation establishment, and school in Baghdad, Iraq established in the 700's), al-Khwarizmi is known as one of the most famous mathematicians at the House of Wisdom.

Inspired by the Islamic Tilings, I tried to create a tessellation with the letter K.  Seeing that could be rather challenging, I decided to think of letters or numbers that might fit easily together.  The number 4 came to mind.  Since my daughter is involved in 4-H, I thought I might be able to use that combination of numbers and letters for a tiling.  My original attempt at this tiling failed because the stem of the 4 was not long enough to allow for the tiling as I was picturing it.  When I extended the stem of the 4 - "Eureka!" (oh, wrong mathematician - Archimedes said that!), it worked!  I was able to tile in the H along side of the 4, separated by a hyphen (light blue square).   Here is the tiling I created:


After exploring al-Khwarizmi on my own, he became very interesting and inspirational to me.  I saw the depth of his workings in so many facets of math:  history, nature, communicating, and doing math.  Prior to being introduced to this brilliant man in my math capstone class, I had not realized that Islamic mathematicians had such a profound impact on math as we know it today.  Al-Khwarizmi sparked my interest in math history, a subject I have usually steered clear of.  I thought, if this guy is so interesting, and his math ideas are so engaging, then there must be other mathematicians who are also intriguing and fascinating.   Al-Khwarizmi is the reason I decided to do my semester project about the great mathematicians throughout history.  Math history anyone?