You can’t hide from the primes

The Intrepid Mathematician

What are primes?

A prime number is a positive integer with exactly two different divisors. For example, 2 is prime, as 1 and 2 divide it. The same is true for 3, 5, and 7. But 6 is not prime as it has four divisors 1, 2, 3 and 6.

Image result for ulam spiral The Ulam spiral, where colored cells are primes. A larger version is the featured image of the blog.

On first glance, we may think that primes are not so useful. After all, we don’t use primes in daily life. Or do we? Read on!

First, we provide a few basic and not so basic facts about primes.

  • A handy fact: to determine that a number n is prime, check for prime divisors at most √n. For example, we can quickly determine that 83 is prime by checking that 2, 3, 5 and 7 are not divisors.
  • Every number is a product of primes. For example…

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A perspective on teaching mixed attainment

mho maths

In a world first for this blog, I have a guest post!

The power of collaboration and Twitter has led me to Bruce Gray (@bucksburnMaths)  who teaches in Bucksburn Academy in Aberdeen.  I am a recent convert to teaching mathematics in mixed attainment groups rather than sets but I am a pragmatist at heart and fully understand the reservations and difficulties with this approach.  It is not a small decision for a maths department to switch from teaching in sets to mixed attainment groups, especially if other subjects retain sets as my school does.  My summary of how to do it which I have written about before:

  1. Collaboration and co-planning must be part of it 
  2. Do it one year at a time, i.e. start in Year 7, and review each year

To find out more, check out www.mixedattainmentmaths.com.  The first #mixedattainmentmaths conference was held in January and plans are being…

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This is fun…but is it math?

Mrs. von Oy's Math Blog

A few months ago, I got an email from one of the art teachers in the school.  She was offering her classroom, a makerspace of sorts, and her creative expertise to any teacher that wanted to bring their class down.

I jumped at the opportunity.  After all, what have I been enjoying most about math lately? Making and appreciating #mathart.

So. We brainstormed and ultimately settled on doing a project that would lead into our upcoming similarity unit.  It would have the kids constructing equilateral triangles descending in size, alternating colors, each triangle with a side length the same as the height of the previous triangle.

The students had never done constructions before, so it was a good introduction to using a compass, and it was also a chance for the students to play with the artistic concepts of structure, contrasting color choice, and composition.  The kids had fun, and…

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