Try this...

If you have a 7 digit phone number (North America anyway) try this…

  1. Grab a calculator

  2. Key in the first 3 numbers of your phone number
    (not your area code)

  3. Multiply by 80

  4. Add 1

  5. Multiply by 250

  6. Add the last 4 digits of you phone number

  7. Add the last 4 digits of your phone number again

  8. Subtract 250

  9. Divide number by 2

  10. Check out the answer !



How did that Work?!?!?

It’s a posh way of adding 1 then taking 1 away. Notice add 1, multiply by 250, take away 250. And 250*80 is 20 000 which when divided by 2 (notice last 4 are added twice as well) is 10000 which is what you need to multiply the 3 digits by to put them at the start. (123 to 1230000).

And yes, I realise I put too much thought into that, but it was either that or maths coursework.


Wow! and i thought he only made unicycles.

I don’t think it worked for me.
I got 17845653 the two times I tried it, and I don’t think that means anything.

that’s 8 digits. Where you start with the first 3 digits try it with the first 4.


That is amazing because it is my phone number times 3.14159 then divide by 2 then add 34,564 then substract 123,442.453

oh no, why did you do that??? it came out to be my phone number, now everyone will know it!!!

Please don’t prank phone call my house, my parents will be really mad.


Meh, you and you mathematics boys. But I’ve memorised pi to 60 decimal places.


And you’re just gonna have to trust me that I learnt that. The secret for me was to learn it in 5 digit blocks. I just did that in like one maths period (50 minutes or so) when I was bored because the work was too easy. I thought it would be hard but it was easier than I expected. If you group them into 5’s lots of similar things seem to pop up, like at the start of 2 different sets of 5 they both start with a 26, and one beofore the second 26 starts with an easy 23. 79 pops up twice that I think of when saying it out loud. And 69 is the start of one which is just an easy one to remember. And the last block of fice, 74944 has three 4’s in it, so it’s quite easy.

Please note: if you are using excel or something to find it out to exactly 60 decimal places you may find that the last digit may be rounded up, this is just because I learnt it off a poster that has it up to 75 decimal places.

what’s the world record at the moment?
are u going to continue learning it and see how far u can go?

There are a few similar records here:

It is a lot :astonished:

Just when I thought it was pretty good going to 60 somebody has done 42,195. That really annoys me. Oh well, I’m just gonna take it as far as I can go, it’s probably quite benefitial for my memory. I was amazed how easy it was, that in like an hour.

I’ve memorized about 40 decimals of pi, and 11 decimals of e. I’m still working on e.

Yeah, but now that trick worked for me. It’s pretty cool.

I knew a couple of folks in high school who used to memorize pi. They did it as you are, by blocks, and memorized at least 10 or 20 every morning. By the end of school one was up to 4,000 and the other was over 6,000. This was about 1976 so I’m surprised I didn’t see either one of them in the world record list.

Anyhow, good luck. Persistance is the key. Rick said that after a while the numbers became like music and they sort of sang in his head like a tune.

Pi day

Happy Pi day to all you weird-o’s.

March 14.