## Wednesday, April 30, 2014

### W, X, Y, Z (all rolled into one for end of the A-Z blogging challenge)

Wow, it is the last day of April already!  I've had sick kids and I've been sick so it was really hard to make any posts the last few days...  Oh, well.  Remember when you learned the alphabet song and WXYZ always get squished together anyway?

W is for word problems
X is for xyz drawings
Y is for Yff central triangle
and Z is for zero!

Do you know how many math terms start with these letters of the alphabet?  Very few, so some of these are a bit of a stretch (you probably wouldn't teach elementary kids the Y term but it wouldn't hurt).
* * *
W--word problems.  They are sometimes dreaded by students, but that might be that they don't want to read the words in the problem.  I have seen my own kids' teachers tell students to look for keywords and that is okay, but I know one of my children thinks he can skip reading the scenario and just look for the key words and at the numbers given among the words.  Hopefully, we can emphasize that it is important to understand the whole question by reading every word. : )

One of my favorite activities regarding word problems is for kids to create a word problem out of an equation.  Give students a problem like this 3 x 5 =  _   and see all the variety of word problems they come up with.  To be extra challenging make the missing number in the middle.  16 = _ + 4
* * *
X for xyz drawings.  What is it?  It is a 3-dimensional drawing of points that are along the x, y, and z axis.  You've probably seen students make something like this before...
Have kids draw that on paper and it is an xyz drawing!
* * *
Y for Yff central triangle.  Never heard of it?  Don't worry.  I had to search to find a Y math term but there were quite a few Yff terms.  Peter Yff was a math person who studied triangles in the 1980s.  There is a wikipedia article about Yff center of congruence, Yff central triangle, and more here.  So, if your students want to make a similar Yff central triangle (it is probably above their level to make it the exact central triangle).  Take a length along a triangle and take that same length along each side of the triangle.  Take that midpoint and connect it to the opposite vertex.  The point where the three lines meet is an approximate Yff central triangle!

* * *
Lastly, Z for zero.  Zero often means nothing but the digit zero can be an important placeholder.  I wouldn't mind having \$1 followed by six zeros, would you?  Have you read the book A Place for Zero (Charlesbridge Math Adventures)?  It is pretty fun.  Also, did you know about googol?  The number 1 with 100 zeros behind it.  It was the number that inspired the name of the company Google.  There is a book titled Can You Count to a Googol? (Wells of Knowledge Science) that puts things into perspective a bit (I think it is so difficult to truly comprehend huge numbers).

Well, it was fun and challenging to do the A to Z blogging challenge.  I hope you enjoyed this year's posts of math terms!