# 1 not prime

Discussion in 'Mathematics' started by mathmo2000, Feb 12, 2011.

1. ### mathmo2000

Sorry to be an **** but just been browsing resources on TES connect where I found a maths toolkit by Shotton Primary. They have incorrectly stated that 1 is a prime in their glossary of maths terms. A basic error really!???

2. ### DMNew commenter

Tell them not us!

3. ### florapost

all too common tho - had - erm - discussion with home-ed worksheet site on this - i quoted wolfram to them - they quoted wiki answers back!!!!

4. ### Andrew JeffreyNew commenter

Amazingly, I am friends with HT of Shotton Primary - I will mention it to her! She is amazing and would be quite happy to be corrected.

5. ### DMNew commenter

You know everyone and everyone knows you Andrew. This I know to be true.

6. ### weebecka

There are some Royal Institution Christmas Lectures which were sent to all secondary maths depts (the de Sautoy ones). In lecture one he explains why one is not a prime really well with activities to show how the primes generate all numbers and why 1 doesn't work in the same way.
If I remember rightly 1 was a prime at some stage in history wasn't it?

7. ### anon2799New commenter

Blimey, that must make me a nobody then

8. ### DMNew commenter

He knows you curly. He has just decided you are best avoided.

9. ### erm

which site, flora?

10. ### anon2799New commenter

hahah my reputation goes before me!

11. ### florapost

have pm'd you

12. ### Andrew JeffreyNew commenter

Sorry. I didn't mean to imply I knew everyone. It's just a coincidence that I know the head of that particular primary school! Not sure whether we have ever met, CG!

Weebecka is right about the RI Christmas lecture. Marcus Du Sautoy explained that 1 was prime until around 1824(?) when it was proposed that it should not be as primes were the building blocks from which all numbers could be made by multiplication.

Obviously 15 for example is 3 x 5, but it could also be 1 x 1 x 3 x 5 1 etc. so 1 was dropped.

That was the one where he did the brilliant sieve of Eratosthenes by exploding balloons!

13. ### DMNew commenter

You wouldn't have been able to explode any balloons andrew as you missed the point entirely. I was fawning at you and having a "pop" (tee hee) at curly at the same time.

14. ### DMNew commenter

My God! I am a one-man pun machine.

15. ### florapost

it's one of the things we love you for

16. ### anon2799New commenter

Indeed. Don't have a pop at me DM, I'm well 'ard

18. ### DMNew commenter

You're a dog?

19. ### anon2799New commenter

Now that was very rude!

20. ### DMNew commenter

Hard nuts have thick skins.