Category Archives: Math Content

Ninety-Ten

90-10We were playing this game in math class today called “I have, You need” during which the number ninety-ten came to my attention.

The game is pretty simple – one person thinks of a number between 1 and 99 and the other person comes up with the number that will add to that number to make 100. Warming up we start with numbers like 30, 45, 75 etc. Then we move on to more difficult numbers like 37. Many students will think first that 73 is the matching pair. This is because they want to make 100 and they know that 30 and 70 go together. When I explained ninety-ten, the problem became much easier. They were now trying to make nine tens, so 63 was immediately identified.

Sometimes we need to think about numbers a little differently. From place value to working from left to right, there is much more freedom in math than we’ve been led to believe. Create something new!

101qs

955-san-francisco-house

What’s the first question that comes to your mind?

Dan Meyer, prolific blogger, high school math teacher, and current Ph.D. student at Stanford wants to know. Dan has decided that there are way too many artificial scenarios in his high school math texts that pretend to model the world. He wants to see the real world in his math class because he sees the math in the real world.

101qs.com is the brainchild of Dan Meyer. On this site, anyone can post an image or a short video and let the world ask the math questions that naturally arise from the scene.

From this, he and many of his followers have created lessons where the students can generate the questions (probably the ones that the teacher has in mind), ask for any relevant information they need, and solve real problems the way they would in the real world.

It’s fantastic – check it out, but don’t be surprised if you find yourself seeing math problems everywhere.

How about this one?66-the-ticket-roll

How many do you think there are? What number is just too many? What number is too few? Be brave.

What do you need to know?

Math Anxiety and Fluency

stress

Math anxiety is real and it affects about half of the U.S. population. Brain imaging has shown us that stress gets in the way of working memory, which is typically required to do mathematics. In fact, math anxiety seems to affect people with a high amount of working memory most! One of the main sources of math anxiety is the stress produced by timed tests (Boaler, Education Week, 7/3/2012).

I used to have my students take timed multiplication and division tests to practice fact (computational) fluency, but I don’t do this anymore. Time is too heavily factored into the measure of fluency in that equation. Rather, I have students learn and practice strategies for working with numbers so that they can be fluent.

Here’s a tip for developing the habit of seeing patterns in numbers: spend more time looking for patterns in math homework and throughout school mathematics. School math is designed to illustrate patterns! Though this is sometimes a weakness in that a framework is often given and problems are explicitly trying to illustrate relationships, this will help students (who attend to these patterns) develop strategic thinking.

Take for example two problems from last night’s homework.

  1. Kaden divided 96 by 12 and then multiplied by 6. Write an expression to show the problem. Then, solve the problem and write an equation.

When most students first approach a problem like this, they begin to decode or solve it step by step. First they do 96 divided by 12 getting… what is that anyway? And then they multiply by 6.

When I look at that problem, the first thing I notice is that 96 is being divided and multiplied. These are inverse operations – meaning that they undo each other. If the problem was 96 divided by 12 times 12, I hope we would just leave it at 96 because we all know this doing and undoing relationship. In this case, the situation is only slightly less humorous (mathematically speaking). If we are going to divide 96 by 12 and then multiply by 6, then we are undoing the dividing by 6! This leaves a much simpler expression: 96 / 2 (96 divided by 2). The equation I would write would read 96 / 12 * 6 = 96 /2 = 48. That’s number fluency.

  1. 81 – (9 * 7)

Here too, most of my students given this for homework followed the “proper steps” and dutifully multiplied 9 * 7 and then subtracted that from 81. This misses a beautiful relationship embedded in the problem. If you notice that 81 is also a multiple of 9, you can rewrite the problem in the following way.

81 – (9 * 7) = (9 * 9) – (9 * 7)

We are subtracting 7 groups of 9 from 9 groups of 9. The difference is 9 * 2.

When most people think about what mathematics is, they think about memorization and procedures. I think this is what it felt like coming through the system for a lot of people in my generation. Today, in many classrooms around the world, math is taught around understanding ideas, discovering relationships, exploring patterns, and developing strategic thinking and problem solving skills.

The difference between memorizing a bunch of rules and procedures and coming to understand mathematical ideas and principles is profound. Memorization requires no real reflection or ownership. There is often very little connection between the learner and the material. As a result, the learning is shallow and has very little application outside of school for that student. Teaching number fluency with conceptual understanding on the other hand requires more engagement with the material. It challenges students to come to terms with a deeply interconnected and vibrant discipline. I believe it also opens the door to a real relationship with mathematics that can help students avoid math anxiety.

Mathematics is sometimes called the science of pattern and order. This is exactly what draws people to math – let’s keep that perception of the subject alive when we are actually doing math work.

Algebraic Thinking

alh-1a

One of the most exciting things for 5th grade students is learning about algebra. They have been anticipating this subject for some time. What’s interesting is that they have been working with abstract mathematics forever, but it just isn’t often called algebra.

When we ask: 5 x 5 = ?, this could be written 5 * 5 = X sometime early on in elementary school. This introduction to variables can be a huge stumbling block for many students. It’s really important to get comfortable with variables in mathematics early on. We can make this problem slightly more difficult by asking it another way.

5 * X = 25 or finally 5X = 25 – now we’re doing simple algebra.

This week we have been looking at systems of equations and solving for all of the variables. These are wonderful problems that help students get familiar with variables in equations.

Here is a sampling of some of the problems we have worked on. Feel free to create some on your own. As long as you have a unique equation for each variable, there will be one and only one answer.

A + B + C = 36

A + A + B = 26

B + B + B = 18

The next problem we tried was

2A + B + C = 48

A + B + C = 40

2B + A = 18

At least one class tried this one

2/5A + B = 17

A + B = 20

And most challengingly some attempted the following

2A + B + C = 30

A + 2B + C = 35

A + B + 2C = 37

 

Wow! Stanford Online Class for Kids

Check out this amazing opportunity! This would be a wonderful thing to do with your child. Professor Jo Boaler is an exceptional mathematics educator and is offering this class for free. Class starts in late May or early June and can be completed at your own pace at any time through December 2014. This could be your summer math plan…

https://class.stanford.edu/courses/Education/EDUC115-S/Spring2014/about

About This Course

How to Learn Math is a class for learners of all levels of mathematics. It combines really important information on the brain and learning with new evidence on the best ways to approach and learn math effectively. Many people have had negative experiences with math, and end up disliking math or failing. This class will give learners of math the information they need to become powerful math learners, it will correct any misconceptions they have about what math is, and it will teach them about their own potential to succeed and the strategies needed to approach math effectively. If you have had past negative experiences with math this will help change your relationship to one that is positive and powerful.