# Math Teachers at Play #89

Welcome to the 89th edition of Math Teachers at Play (MTaP) Blog Carnival!  MTaP is a monthly blog carnival with a collection of tips, games, and activities for teachers of students of all ages.  If you haven’t seen the carnival before, you can read the previous posts.  I also hosted the 82nd edition.

89 is…
• the 24th prime number
• a Fibonacci number
• a Pythagorean prime
• the atomic number of actinium

89 appears in TWO Pythagorean triples!  Comment if you know what they are :)

Now, for the posts!

## Elementary Concepts and Arithmetic

Leigh, from the Applicious Teacher, explains a technique for helping students solve multi-step problems.  She also shared an interactive notebook idea to support the lesson.

Students always seem to panic when they see fractions.  Scipi uses pattern sticks to help students reduce fractions without the panic.  They can also be used to change improper fractions to mixed numbers.

Brandi, from The Research Based Classroom, shares a fun game called Help Your Neighbor.  It is a game that helps students practice adding numbers from 1 to 12.

## Beginning Algebra and Geometry

Scipi explains in her post why FOIL isn’t the best way to teach students to multiply binomials.  FOIL only works in the special case of multiplying binomials.  Scipi proposes an alternate method that works when multiplying any polynomials.

I always spend some time in Geometry with optical illusions.  This post explains why.

A post on Leaf and STEM Learning explains the faults with teaching PEMDAS.  An alternative mnemonic is shared with a foldable that can be used in interactive notebooks.

Envelopes
The National Curriculum in England and the Common Core in the US both require students to develop Fluency, Reasoning, and Problem-Solving.  Alan Parr shares an old activity made new and relevant.  It has proved successful in stimulating high-quality discussion which benefits all three.  You can follow Alan on Twitter:  @piogold

Ellie, from Middle School Math Moments, shares a discovery activity for teaching slope.  Students were asked to find relationships between equations and graphs.  She even shares the handout she used in class.

Jonathan Claydon from Infinite Sums gives a great explanation of how he teaches polar coordinates in Pre-Cal.  Not only does he explain how he teaches the lesson, but also gives activity ideas and links a great video.  If you’re teaching polar coordinates this year, you need to check out this post.

Need an idea about teaching linear regression?  Jean from Flamingo Math explains how she uses TI-84 calculators to help explain linear regression to her students.

## Mathematical Recreation

On the blog Everything Education, a fun idea is shown that can help students think creatively.  Obviously false mathematical statements can be given, and students must come up with situations where the statement might be true.  Read the post to find out more.

Denise from Let's Play Math shares a number puzzle.  What pattern can you find in the number puzzle?  Every answer is right - just be sure to explain your reasoning!  You can follow Denise on Twitter:  @letsplaymath

Do your students love Minecraft?  Rachel K shares a list of activities and games on Minecraft that can reinforce mathematical concepts.  There are lots of ideas from basic addition to area and perimeter.

Creative Cake-Cutting:  Divergent & Convergent Problem-Solving
This post by Maya is based on a non-routine problem about cake-cutting.  Two distinct solutions are presented, and various questions about their makeup are presented.  There is a little something for anyone involved in math with this post.

If you want to include math history in your classes this year, Birgid from Math Giraffe has you covered.  She will be tweeting out facts every Friday so that you can have them prepared for the upcoming week.  Read her post to find out more!

5 Math Gems #36
Jo shares part of a series of gems posts which share five math teaching ideas.  THis post features an area maze, warm-ups, Desmos activities, pixel puzzles, and a Geogebra tool.  You can follow Jo on Twitter:  @mathsjem

Randi, from 4 the Love of Math, relates her fear of public speaking to student’s fear of math.  Math is important.  She explains how teachers can help students overcome their phobia.

My Top 7 (+1) Math Activities
Laura is a new(er) blogger who has some fantastic ideas on teaching middle school math.  In this blog post she shares some of her favorite class activities.  Many of these could be adapted for high school as well.  You can also check her out on Twitter:  @lauriebworthy

Task cards are great and keep kids engaged.  If you need any ideas on how to use task cards in your classroom, these two posts may help.  You may find a new idea to try this school year!  You can follow me on Twitter:  @mrseteachesmath

Jennifer from Teaching High School Math explains a technique for helping students become more proficient about explaining mathematical ideas.  Students have a hard time explaining math and these ideas can help!

The Carnival of Mathematics is another blog carnival that you may enjoy.  You can check it out here.

I hope you enjoyed this issue of Math Teachers at Play!

1. What a great collection!! I'm finding so much great stuff in here. Thanks!

2. Since you mentioned 89 as a Fibonacci number:
1/89 = 0.011235...

I don't know of any Pythagorean triples with 89, but I know the following works:
a^2 - b^2, 2ab, a^2 + b^2

Every odd number can be written as a difference of consecutive squares, so there must be a choice for a^2 - b^2 = 89.
89 is the 45th odd number; so how about: 45^2 - 44^2 = (45+44)(45-44) = 89(1) = 89. Yes!

This worked with a=45, b=44; so the triple is:
89, 3960, 3961

Hmm... and 89 = 64 + 25 = 8^2 + 5^2 ...

Somehow, the smaller numbers arrived later!

Here we have a=8, b=5; so the triple is:
39, 80, 89

MQ

3. mathwater, you got it!

4. I am very excited that you are sharing my order of operations blog post!

5. Fabulous set of ideas. And thanks for the share of the creative math thinking post...

Cheers,
DocRunning

6. Thank you so much for sharing my post.

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8. In math teachers play we have seen many of the guidelines and ideas they used to differentiate each other and also used to develop within themselves students who can perform and understand basic elements to the right direction. teaching statement of purpose

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