# Posts and Ideas I like

Tuesday 12th November:

Great Probability problem about random seating on planes.

Tuesday 5th October:

“You will spend 3-4 years on your smart phone during your life.” – Good investigation.

Monday 7th October:

Hitting the nail on the head with Maths Education – Conrad Wolfram.

Sunday 6th October:

Great little youtube video on Mathematical proof!

Monday 16th September:

I really like these reflections from a teacher who asked his students to write an autobiography.

Friday 6th September:

Four classic number conjectures that everyone can understand but no one can prove yet.

Thursday 5th September:

Inspiring TED Talk on Prime Numbers.

Monday 2nd September:

Vector Mazes – interesting way to get students practicing and creating at jensilvermath.com.

Sunday 1st September:

Great puzzle (possibly for 6th or 7th graders) at Fawn’s blog.

Saturday 8th June:

Great example of why accuracy is so important in mathematical calculations. Spanish Navy make a decimal point error which costs £14,000,000.

Thursday 30th May:

Brilliant presentation on “Maths is not Linear” by Alison Blank.

Thursday 23rd May:

1. Learning to use Excel to make a problem easier to solve – The Divisibility Problem (Teach Maths)

2. Ratio and Proportion when embedded Youtube videos on a blog – great idea at Math and Multimedia.

Thursday 16th May:

Tuesday 14th May:

Can you draw a circle on a World Map which contains half of the World’s population?Posted by Bill Gross.

Wednesday 10th May:

The reason why ratio and proportion is important.

Wednesday 9th May:

1. Holy Craps! How a Gambling Grandma Broke the Record – 154 rolls of two dice without getting a 7 – great way to get students excited about probability at mathcoachblog.

2. Practical activity – getting the students to figure out proportions of the class that would and wouldn’t have things based on World Statistics. (done at teachmaths)

3. Get the students playing golf outside, or snooker, to figure out where to hit the ball off the side when something’s in the way (Finding ways to Nguyen students over).

Sunday 5th May:

Great Ted Videos on Zeno’s Paradox (connection with Geometric Series) and the Mathematics of On-Line Dating (Connection with Geometric Mean and Algorithms). Interesting Project, how would you measure how well suited two people are?

Wednesday 2nd May:

1) Great History of Maths video at Math Fail.

2) Visualizing the World’s food consumption and proportion of income spent on food.

Thursday 25th April:

Joseph Flavius game – interesting investigation (found at gfsmaths)

Wednesday 24th April:

Sunday 14th April:

Dancing vectors as an exciting way to introduce vectors at Teach Maths.

Thursday 11th April:

Starting with the context and then getting students to beg for the mathematics that will make it easier. Forming and Solving Quadratics at Fawn Nguyen’s blog.

Tuesday 9th April:

Well communicated, rigorous proof of the derivative of sine at Math Mama Writes blog.

Friday 5th April:

Great article – which path would an ant take to reach food? http://phys.org/news/2013-04-ants-fermat-principle.html (Connection to Dan Meyer’s Taco Cart Problem)

Tuesday 2nd April:

An excellent summary of Assessment for Learning at Pragmatic Education.

Wednesday 6th March:

Introducing Real-Life Graphs

Fun video to introduce graphing a real situation – at Nat Banting’s blog: Musing Mathematically.

Wednesday 27th February:

Conditional Probability

Excellent picture hook for Conditional Probability at Great Maths Teaching Ideas.

Tuesday 26th February:

Pi Song

Play this song when students are coming into a lesson about circles.

Monday 25th February:

1. Euclid’s Elements free, interactive, online.

2. Lots on interesting problems.

3. Interesting Idea: Little, C. (1999). Teacher to Teacher: Geometry Projects Linking Mathematics, Literacy, Art and Technology. Mathematics Teaching in the Middle School, 4(5), 332-335.

Saturday 23rd February:

1. Explore properties of polygons by giving students a rope, asking them to make shapes – such as an irregular nonagon or regular hexagon.

2. Introducing Enlargements – show the picture below and ask them what they think. Investigate on Geogebra. Good idea from Inquiry Maths

Wednesday 20th February:

Making Multiplication Fun

See some solid ideas to make multiplication fun and improve understanding and recall at Mr Reddy’s Math Blog.

3 ACT Maths – Super Mario Non-linear Function

3 ACT learning activity provided by Nora Oswald on her blog Simplifying Radicals.

Sunday 17th February:

Great clip – Mathematicians discuss conjectures over coffee, often making mistakes.

Friday 8th February:

Dancing with Curves

Tuesday 5th February:

Direct and Inverse Proportion

Some nice unituitive problems to discuss direct and inverse proportion. (Cat and Mouse Problem)

Friday 1st February:

Estimation in Real Life

Questions from nrich to aid discussion on estimation. (http://nrich.maths.org/7418)

Sunday 20th January:

The Forgetting Curve

Nice way to show an exponential decrease which isn’t radiocative decay – at Great Maths Teaching Ideas.

Wednesday 28th November:

Diamond Collector – Nrich

Great Applet for consolidating equations of straight lines – fun game at nrich.

Monday 26th November:

Rationalising the Denominator – Extension Task

A nice little extension question on rationalising the denominator at Nrich.

Friday 18th October:

Shape Properties Activity

Connect four activity from Kristen Szerszen Kaminski (@alevelup) – brilliant idea!

Saturday 6th October:

Probability lesson

A nice lesson from Miss. Radders at ideasfortheclassroom. Show a clip of Derren Brown’s show, “The System” and ask the students what the liklihood is of getting 10 heads in a row and how Derren managed to do it in one attempt.

Wednesday 3rd October:

Great Surface Area Question – Tweeted by Mr. Taylor (To infinity…and beyond)

Tuesday 2nd October:

Nrich: Modelling an Epidemic

Nice way to introduce modelling and exponential functions to a class/year group.  Start off by infecting one person and asking them to stand up. They then infect the two people closest to them and it carries on until everyone is stood up. Lots of great questions and modifications that could be investigated. Nrich – Investigating Epidemics.

Monday 1st October:

Volumes of Revolution in Geogebra

Daniel Mentrand, I salute you! Awesome Geogebra File for Volumes of Revolution around the x-axis.

Monday September 24th:

Always, sometimes, never,…

A nice activity at The Feedback Loop blog written by Sarah Aldous. Write statements on cards, such as “At least one adult in a group has an income which is the same as the mean income for the group.” Ask students to put the card into a column in a table with headings: always, sometimes, never and then discuss this as a class. A great way to promote some rich discussion!

Saturday September 22nd:

Show me 31/100…

A great way to assess students knowledge with fraction, decimal or percentage work is to ask them to “Show me 31/100,” and simply see what they come up with. You could do it on the board, use multi-link cubes etc. This is a nice idea from Bruce Ferrington at Authentic Maths Inquiry that I’m definately going to use!

Monday May 21st:

Learn to Computer Program with Fun Programming

I came across the Fun Programming website a few days ago. It’s a great site with over 100 tutorial videos to help people learn the processing computer language; a slightly simpler language to start off with if you want to learn how to program. This would be a great resource for students to use in schools – definately something that I’ll be advocating in my own school.

Sunday April 22nd:

Geogebra Applet: Intuition on the Chain Rule of Differentiation

Marc Renault has done a great job so far with his Calculus Applets Project in which his goal is to make a complete library of applets for Calculus that are suitable for in-class demonstrations and/or student exploration.

I particularly like the applet he made to increase understanding of the Chain Rule. Check out the link to see for yourself.

Sunday April 15th:

Pi, Tau or Eta: Which should be the fundamental circle constant?

Michael Hartl points out that a circle is the locus of all the points equidistant from the centre so it makes more sense to use the constant tau, which is the Circumference divided by the radius, as opposed to pi, the circumference divided by the diameter. It certainly makes understanding circle angle meaures and Euler’s formula easier in my opinion.

A few people don’t agree that pi or tau should be used as the fundamental circle constant but that it should by eta which is tau/4 or pi/2. This does make multiplying by i (imaginary number) a more intuitive 90 degree rotation.

I guess the ultimate conclusion is that that different constants can be used to increase understanding of different situations.

### 2 Responses to Posts and Ideas I like

1. Peter Azzopardi says:

Hello i believe i have found another way of calculating the value of the circumference here is a small example of what i mean as we know C=2pi.r so if the radius is 10 cm then we have 6.28×10=62.8 but i have found another way and it is based on these two numbers 157/50=3.14 and also 157/25=6.28.
Therefore 157×10/25=62.8 another example 6.28×7=43.96 but also can use 157×7/25=43.96 now i have a picture that illustrates the reason for this and in fact you can try it for anything else with a slight variation of order you can get the circumference off curved shapes ellipse oval oblate prolate sphere and so on if interested to find out more please contact my email so i can send an illustration of this matter,you can use it it’s very simple and it doesn’t require calculus!!! just simple childish arithmetics,hope you reply please sir if you would be so kind,looking forward for your response!!! yours sincerely Anthony Peter Azzopardi.

• Hi Peter,

I congratulate you for thinking about things in different ways. As you may already realise, your way of doing it is the same as using pi, only you’ve used an approximation of pi (157/50) instead of the whole thing. The ancient Chinese and Babylonians and of course the Greeks all used approximations of pi ( a well known approximation is 22/7 = 154/49 very close to your approximation) because they didn’t have computers to calculate it to a more precise level.

I’d love to see the geometrical representation you mention! My email address is daniel.pearcy@teachfirst.org.uk