## Saturday, August 22, 2015

### Common Core Math for Parents for Dummies Book Recommendation

The author of the book, Christopher Danielson, (on Twitter as @trianglemancsd), does a comprehensive job of summarizing and interpreting the Common Core standards for grades K through 12. As someone who has only taught grades 6 to 8, it was great to see how the standards progressed. I also am now much more able to answer anyone's questions about the standards.

Don't be thrown off by it being for parents, or for dummies for that matter. This book is for teachers, administrators, and of course parents and anyone interested in math education. I actually was obsessed with Macs for Dummies and the author David Pogue as a teenager and love the style of the book and the readability.

I took notes on interesting points from the book and some questions that I have. One topic I liked when he discussed fractions was common numerators. We don't talk about being able to compare fractions with common numerators ever such as what's bigger, 2/3 or 2/4. He also talked about how you can't compare two different units, it's like comparing apples and orange. He also pointed a confusing yet commonly incorrectly solved order of operation problem that is 48 / 2(9+3). I got it wrong the first time too.

An interesting question to ask a 5th or 6th grade class is: why is there no such thing as a LCF or GCM (least common factor or greatest common multiple). This will create a very interesting discussion about vocabulary.

When talking about statistics, a cool way would be comparing heights of 5th and 6th, or 6th and 7th graders at a school. The Common Core does call for mean absolute deviation, though I am still unclear about the applications and what type of context it could be introduced to students in.

I liked the idea of having a discussion of how old your dog is, in dog years and human years, and reason how and why they are different. I honestly can't remember off the top of my head unless I looked at the relationship of two examples.

In 7th and 8th grade classes I have found myself label 2/3 as a decimal, as 0.666... and call 6 the repeating part so you only need a bar over the 6. Well, there is actually a name for that. 6 is the "repetend," the repeating part of a decimal.

One question I had, was in 8th grade he said the standards introduce point slope form. In CPM's Core Connections 3 curriculum there is no mention of this form, only standard form and slope-intercept form. So, I am a bit concerned that I did not cover that last year.

Lastly, I was very pleased in the Pythagorean theorem section he mentioned the distinction between acute and obtuse triangles side lengths. I brainstormed before how to keep students from not remembering which way the inequality sign faced, the two legs squared and added together or the hypotenuse squared. Apparently he thought about this too, because he showed the most common acute triangle you can think of: an equilateral triangle. Which we know has equal sides and is equiangular at 60 degrees each. So, if you have sides of 2. 2 squared plus 2 squared is 8. The last side, 2 squared, is 4. So, clearly, if the hypotenuse squared is smaller than the triangle is an acute triangle. I hope that made sense. It makes sense when you draw a picture.

Oh yes, and the best anecdote of the book was when the author's son got an increase in his bed time on his birthday. So, his son saw a pattern and reasoned he could predict how late is bed time would eventually go. Great example of #tmwyk (talking math with your kids) unprompted.

All in all I enjoyed this book and would recommend it to any math teacher, administrator, or parent at any grade level. It gives you tips on how you can help your student think mathematically and how to help them without doing their homework.