## Archive for June 14, 2013

### Math Teachers at Play 63

Hmm… let’s see… now where did I put my notes? I know that this is supposed to be the *Math Teachers at Play* blog carnival… but which one?

Maybe the following puzzle will help. In the grid below, do the following:

- Circle any number, then cross out the other numbers in the same row and column.
- Of the remaining nine numbers, circle one, then cross out the other numbers in the same row and column.
- There should now be four numbers remaining; circle one. Then cross out the other numbers in the same row and column.
- There should now be one number remaining. Circle it.
- Calculate the sum of the four circled numbers.

Pretty cool, huh? Try it again, and you’ll find that the sum of the four circled numbers will always be 63. Can you figure out why it works?

Ah, yes! That’s it! This is **Math Teachers at Play 63**! Good day! Welcome one and all!

You might wonder why I’d start this carnival with so many questions. Maybe it’s because 63 is the ASCII code for a question mark.

Other interesting facts about 63:

- 63 = 7 × 9.
- 63 = 2
^{6}– 1 = 1 + 2 + 4 + 8 + 16 + 32. - The record for the longest field goal in NFL history is 63 yards–kicked by Tom Dempsey, Jason Elam, and Sebastian Janikowski.
- 63 = 6
^{2}+ 3^{3}. - ‘Rule 63’ is an online adage, which states that every fictional character has a counterpart of the opposite gender.
- In Roman numerals, 63 is written as LXIII; and if you add the position of those letters in the alphabet, you get 12 + 24 + 9 + 9 + 9 = 63. It is the smallest number with this property. (Can you find the only other number with this property?)

**Pre-School**

Trying to help little kids see the fun and usefulness of math, **Beanie N Us** shows her daughter Learning about Numbers at the Car Park and having Fun with Math.

**Elementary School**

At the **New Hope Elementary School**, kids of all ages do M&M Math to learn about graphs, measurement, and area. Yum!

Fraction Folding, Discovery Learning is the first in a series of 16 blog posts that documents what a fourth-grade teacher at the **Fourth Grade Studio** did to help students develop conceptual understanding of fractions.

**Navigating by Joy** shares A Living Maths Approach to Angles using the book *Sir Cumference and the Great Knight of Angleland* and also shows how to have Fun With Tessellations.

When the **Math Mama Writes**, you better listen, especially when she’s questioning how and why we teach vocabulary in Writing, Vocabulary, and Teacher Inquiry.

**Middle School**

Offering straightforward and practical advice, **The Numerist** explains How to Write an Equation of the Line.

Who doesn’t love a story about student success? **4mulaFun** shares such a story from a lesson that has students Reviewing Proportions with WKU. (Don’t know WKU? Neither did I! Read on.)

**Miss Math Dork** shares One of Her Favorite Activities for teaching measurement to middle schoolers, which is sure to become one of your favorites, too!

**High School**

Watch what happens when **Mr. Chase** alternately adds and multiplies in Arithmetic-Geometric Hybrid Sequences.

In** **Probabilities in a Painted Cube, **Cut the Knot** examines solutions to a problem about painting and cutting a larger cube into unit cubes and then considers the historical problem of constructing a line that halves the area and the perimeter of a triangle in Area and Perimeter Splitters in a Triangle.

**Math and Multimedia** share 5 Fascinating Facts About Triangles That Will Surprise You.

Did you know that a Quadrilateral with Congruent Opposite Sides is a Parallelogram? **Proofs from the Book** will show you why.

**Let’s Play Math** tells us How To Master Quadratic Equations, with some assistance from James Tanton’s G’day Math Courses.

**Potpourri**

Are vectors too tough for mental math? Not according to **White Group Maths**, whose Vectors Mental Quiz demonstrates all the stuff you can calculate in your head without reaching for a computing device.

A mom and her kid at **Moebius Noodles** used concept maps to create *Free To Learn* by Peter Gray: Review and Infographics.

Charlotte Mason and Louis Benezet’s Thoughts on Math are documented by **Triumphant Learning**.