One of the hardest questions for many math teachers to answer in a way that is relevant to students is: “why do I need to know this?”  “For the next course you take”, the easiest answer in many cases, does not answer the question that was usually being asked.

My answers to this question obviously depend on the topic being studied at moment, and I don’t have “good” answers for all topics…  but here is my list of key quantitative life skills I learned directly or indirectly from math class, with

I didn’t encounter the Quadrilateral Midpoint Theorem (QMT) until I had been teaching a few years.  Following is a minor variation on my approach to the QMT this year plus a fun way I leveraged the result to introduce similarity.

In case you haven’t heard of it, the surprisingly lovely QMT says that if you connect, in order, the midpoints of the four sides of a quadrilateral–any quadrilateral–even if the quadrilateral is concave or if its sides cross–the resulting figure will always be a parallelogram.

This is a cool and easy property to explore on any dynamic geometry software package (GeoGebra, TI-Nspire, Cabri, …).

SKETCH OF THE TRADITIONAL PROOF:  The proof is often established through triangle similarity:  Whenever you connect the midpoints of two sides of a triangle, the resulting segment will be parallel to and half the length of the triangle’s third side…

The millennium bug or the Y2K bug was going to cause planes to fall from the sky, bank accounts to be wiped out, electricity grids to cease functioning, trains to crash, cars to collide as stop lights stopped functioning, life support units to malfunction and computers to crash around the globe. For years leading up to midnight on New Years eve 1999 consults were paid extraordinary amounts of money to solve the problem.  When the clock ticked over to 1 ^st Jan 2000 nothing much happened. It was, indeed, a non-event, an error in logic.  (Pic from, appropriately, digyourowngrave.com)  

The Maths Error: Guessing the Answer.

Computer programmers represented the year in the date of many programs using two digits but claimed logical errors would arise upon “rollover” from x99 to x00.

While consultants claimed their advice saved the world from catastrophe countries that spent very little on the…

A few weeks ago I wrote a post in shock at the fact that a number of schools in the locality had been teaching rounding wrongly. By this I don’t mean I took issue with their pedagogical approach, but rather that the method of rounding they were teaching was wrong and would result in the wrong answer in some instances. This post received the following comment from Old Andrew (@andrewolduk):

“Is anybody going to raise the obvious issue here that a lot of maths teachers don’t have maths degrees? In recent years the rise of “conversion courses” means that many have a background that isn’t in the least mathematical.”

This stirred up some quite strong feelings on both sides. Sophie Skinner (@miss_skinner) wrote this excellent piece stating her views, and Dave Gale (@reflectivemaths) wrote this piece reflecting his view. Twitter has been buzzing with conversation on the matter, and…

Description: *FREE app at time of post *  Sushi Monster is a ridiculously cute and engaging way to practice math fact fluency (addition and multiplication)!  Students must use their critical thinking and reasoning skills to strategically decide which sushi pieces (each has a number above it) to add/multiply together to feed the monster the total he desires.  Within each round, students see all the upcoming totals in the top left-hand corner so they can plan ahead.  Next to this bar is a Number Sentence bar that builds the addition/multiplication sentence as the student chooses sushi.  If it’s wrong, the monster throws a fit and tosses the sushi plates back!  (What a picky monster…)  Levels within this app are sequenced so that they become progressively more difficult as the student completes them.

Compatible with the following device(s): iPad, iPod Touch, and iPhone

Implementation in classroom:

– Activity idea:  This is a…

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Description: *FREE app*  Although Math vs Zombies is probably meant for children, I found this app to be really fun, especially if there were watching me play and screaming in anxiety!  Basically, cute/quirky zombies are coming to get you, and the only way to change them back into humans (and save yourself) is to solve math equations correctly.  There’s nothing like a little urgency to get those brain juices flowing! Students using this app can choose from four basic operations: addition, subtraction, multiplication, and division.  Within each Operation Level, there are six mini levels and a boss level to beat, and the equations become progressively more difficult between mini levels.  Also, the difficulty level can be set to easy, medium, or hard by clicking on the gear in the bottom left-hand corner of the main menu.

Compatible with the following device(s): iPad, iPod Touch, and iPhone

Implementation in classroom:

–…

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay (though I’m not certain whether this is too late to be put up today).

I’m sorry dearest readers, I think I’ll have to skip an explanation of why I’m inactive on my blog right now for later. There’s just too many plans right now, that all seem to end around May, and if it all goes as planned, you’ll see at least some of the reasons why I’ve been too busy to post here.

Anyway, here’s a Killer Sudoku that was used for the Polish Sudoku Championship qualifiers. These qualifiers were open to International solvers online, so I think many solvers would have seen this already. I still think it’s nice enough to put it up for those of you who haven’t.

Rules – Follow Classic Sudoku rules.
Additionally…

Here are some amazing spiritual math and science facts:

1 + 1 + 1 = 3 when it’s the Trinity. God is three in one! No, we can’t figure it out but God is not limited by the math He invented for us to make sense of our little world. I delight in worshiping a God who is great beyond my understanding .

2 wrongs don’t make 1 right. It’s not like multiplying two negative numbers which gives us a positive.
For example, 1 unintended pregnancy + 1 abortion does NOT equal one “right.” (No one has the “right” to kill a baby—including his/her mother!)

Gravity (physical law) always pulls us down. But glory lifts us upward. Our body is temporal; it has to stay on this earth whether we’re alive or dead. Our spirit can receive God’s never-ending life that give us supernatural power during this life and eternal…

Check out Bedtime Math!

Bedtime Math

Go do a fun Math problem daily with kids of any age! You can also have it sent to you daily. My daughter asks to do her Bedtime Math and so will your kids!!

Have a happy day★

Jamie★

This video explains how to perform stick multiplication and shows how it relates to the method of partial products.

http://en.m.wikipedia.org/wiki/Augustin-Louis_Cauchy

We mentioned Augustin Louis Cauchy in the tragic stories of Galois and Abel. Had Cauchy been more generous and kind enough to submit the two young mathematicians’ papers to the French Academy of Sciences, their fates would have been different and they would not have died so young.

Cauchy was excellent in language. He was the 2nd most prolific writer (of Math papers) after Euler in history. When he was a math prodigy, his neighbor — the great French mathematician and scientist Pierre-Simon Laplace — advised Cauchy’s father to focus the boy on language before touching mathematics. (Teachers / Parents take note of the importance of language in Math education.)

Cauchy’s language education made him very rigorous in micro-details. This was the man who developed the most rigorous epsilon-delta Advanced Calculus (called Analysis) after Newton / Lebniz had invented the non-rigorous Calculus (why?).

Rigorous epsilon-delta…

We all know how terrible homework is and how long it takes and how you could be doing SOOO many other things that are not homework. Like nothing productive. That kind of stuff. And once we actually get started, it’s so difficult to keep on track. Sometimes we hit a brick wall and so we just stop and do something else. And then there are those moments where you have so much work to do that you take a nap. Or the infamous “due tomorrow do tomorrow” mentality. When teachers assign a certain portion of reading you think, “Sweet! No homework!” just because you don’t get credit for actually reading it. This affects almost every single person and extends beyond schooling and even into your real life work. What should you do? Well I can’t tell you, but I can confide in the type of mentality I have and what…

Arcademic Skill Builders :

Free, engaging educational games for students in K-8 to practice skills in math, language arts, geography, and other subjects

Features multiplayer mode so students can practice while competing against classmates in real time

via tumblr published on March 02, 2014 at 05:30PM

I hope that most of you have either asked yourselves this question explicitly, or at least felt a vague sense of unease about how the definitions I gave in lectures, namely

$latex displaystyle cos x = 1 – frac{x^2}{2!}+frac{x^4}{4!}-dots$

and

$latex displaystyle sin x = x – frac{x^3}{3!}+frac{x^5}{5!}-dots,$

relate to things like the opposite, adjacent and hypotenuse. Using the power-series definitions, we proved several facts about trigonometric functions, such as the addition formulae, their derivatives, and the fact that they are periodic. But we didn’t quite get to the stage of proving that if $latex x^2+y^2=1$ and $latex theta$ is the angle that the line from $latex (0,0)$ to $latex (x,y)$ makes with the line from $latex (0,0)$ to $latex (1,0)$, then $latex x=costheta$ and $latex y=sintheta$. So how does one establish that? How does one even define the angle? In this post, I will give one possible answer to…