Welcome to my math blog! The purpose of this blog is to help you stay informed about our learning and experiences that have taken place during our math class. I have also included links your child (and you) may want to use in order to supplement math learning in 5th grade.

## Thursday, February 27, 2014

### Geometry Symbols

We began focusing on geometry today.  We began by learning the basic symbols associated with geometry.  I used a resource from Dinah Zike and included the foldable in the student's math journals:

We defined the following terms:  plane, point, ray, line, line segment, parallel, perpendicular, and angle.  I created a video of the definitions and our discussion for those students who were absent today.  The video is called Geometry Symbols.

Once we had our definitions, we worked with an illustration that included all of these geometry points and allowed the students to prove whether the given statements were true or false.  I found the worksheet in Teacher's Helper - Intermediate, February-March 2012 entitled "All The King's Men".  I took the illustration:

then, gave them this grid:

They were to shade in each box that did not match the figure.  I allowed them to work in table groups.  I walked the room listening to their discussion and their explanations of how the statements were either true or false.

I found a few misconceptions that I addressed IMMEDIATELY:
• Students believed that two lines were not parallel if they were an equal distance apart BUT were not equal in length.
• Students thought lines were parallel just because they didn't intersect.  (I had to demonstrate, using pencils, how the lines would intersect if they were longer).
• Students would assume that any intersecting lines were perpendicular.  They did not focus in on the fact that perpendicular lines MUST have a 90 degree angle.
• Students did not believe lines were perpendicular if they did not look like the perpendicular symbol.  They assumed that it had to have a line that extended beyond where the lines intersected (which negated corners of shapes being perpendicular).
I was pleased to have had the chance to learn about these misconceptions and address them directly with each class!  This activity compromised the remainder of my class time.  We came back together as a class to compare answers and justify our reasoning for the false statements.

HOMEWORK:  Countdown 5.1