A Nifty Math Trick and a Handy Calculator to do it with!

[AffectionateDan]

Just make sure there are no children around when you do this, and turn your speakers on. It's fun, although the math trick itself is a little bizarre! Here's the link for your new favorite calculator...

http://fun.tmc.dyn.ee/org-calc.swf

And now for the trick...

Here is a math trick so unbelievable that it will
stump you. Personally, I would like to know who came up with
this and why that person is not running the country. It's clever!


1. Grab a calculator. (you won't be able to do this one in your head)

2. Key in the first three digits of your phone number (NOT the area code)

3. Multiply by 80

4. Add 1

5. Multiply by 250

6. Add the last 4 digits of your phone number

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

8. Subtract 250

9. Divide number by 2


Do you recognize the answer? Nifty!

 

[milagros317]

That orgasmic calculator is amusing, Dan.

Here is how the nifty trick works:

Let x be the three digit integer which is the first three digits of your phone number. Let y be the four digit integer which is the last four digits of your phone number.

After step 2, you have x.
After step 3, you have 80x.
After step 4, you have 80x+1.
After step 5, you have 20,000x+250.
After step 6, you have 20,000x+250+y.
After step 7, you have 20,000x+250+2y.
After step 8, you have 20,000x+2y.
After step 9, you have 10,000x+y, which displays your phone number, the first three digit in the millions, hundred thousands, and ten thousands columns, and the last four digits in the thousands, hundred, tens, and units cloumns.

These tricks impress those people who won't do the algebra to see how they work. 😀

 

[Moses25]

Yeah, I saw that one too, Mils. Not in the same "exactitude" ( ) as yourself, mind you, but I do believe your influence is becoming stronger for those of us who have an interest in mathematics - and its accompanying philosophy - but are still boobs at it. 🙂

And thanks for posting this Dan. I love doin'em.

Cheers.😀

 

[JPie1]

very cute....Milagros I'd knew you show us the way on this one!!

 

[AffectionateDan]

Yes, very commendable, taking the fun out of it by over-analyzing it...

...wonder what he does for an encore? Lets the air out of Stephen Hawking's wheelchair tires?

 

[milagros317]

There are no coincidences in mathematics; so if something seems to be a coincidence, I do analyze it to see why it is true. 😀

 

[theshire]

That's pretty cool. How do you work something like that out? There was one problem I experienced, though:

This must be an American thing. Here in the UK, phone numbers obviously take a slightly different form. After the county code, there are six numbers. So say my number is 374300 (it isn't, so don't try ringing it 😀 ). The equation thing says that you have to use the first three digits of your number (i.e. 374) and later the last four digits (i.e. 4300). So I got an extra number in my final answer, but other than that, it still came out right.

Thanks, though, to milagros317 for breaking it all down for us.

 

[milagros317]

Thank you, TheShire. 😀

Here is a slight variation that will work for 6-digit UK telephone numbers, without the county code:

1. Grab a calculator. (you won't be able to do this one in your head)

2. Key in the first two digits of your phone number (NOT the county code)

3. Multiply by 80

4. Add 1

5. Multiply by 250

6. Add the last 4 digits of your phone number

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

8. Subtract 250

9. Divide number by 2


Do you recognize the answer? Nifty!

 

[theshire]

Cheers for that, milagros...

Of course, I could have worked that out for myself...

But everything is now right with the world. 😀

 

[njjen3953]

Someone has WAY too much time on his hands. 😛

That orgasmic calculator is amusing, Dan.

Here is how the nifty trick works:

Let x be the three digit integer which is the first three digits of your phone number. Let y be the four digit integer which is the last four digits of your phone number.

After step 2, you have x.
After step 3, you have 80x.
After step 4, you have 80x+1.
After step 5, you have 20,000x+250.
After step 6, you have 20,000x+250+y.
After step 7, you have 20,000x+250+2y.
After step 8, you have 20,000x+2y.
After step 9, you have 10,000x+y, which displays your phone number, the first three digit in the millions, hundred thousands, and ten thousands columns, and the last four digits in the thousands, hundred, tens, and units cloumns.

These tricks impress those people who won't do the algebra to see how they work. 😀

 

[njjen3953]

Someone has WAY too much time on his hands. 😛

That orgasmic calculator is amusing, Dan.

Here is how the nifty trick works:

Let x be the three digit integer which is the first three digits of your phone number. Let y be the four digit integer which is the last four digits of your phone number.

After step 2, you have x.
After step 3, you have 80x.
After step 4, you have 80x+1.
After step 5, you have 20,000x+250.
After step 6, you have 20,000x+250+y.
After step 7, you have 20,000x+250+2y.
After step 8, you have 20,000x+2y.
After step 9, you have 10,000x+y, which displays your phone number, the first three digit in the millions, hundred thousands, and ten thousands columns, and the last four digits in the thousands, hundred, tens, and units cloumns.

These tricks impress those people who won't do the algebra to see how they work. 😀

 

[milagros317]

Jen, that took about two minutes to post, the same time it took to type it. I did the algebra as I typed each line, and knew how it had to come out in the end. 😀

 

[Dave2112]

Gotta chime in here in defense of Milagros. I'm the same kind of person who has to know why things work. It's linear thinking, I guess. I never took auto shop and know little about cars, yet I fix my own stuff by simply noticing that "if this makes this do this, then this must be why this isn't happening."

I love these math things. Math is constant and dependable, and math is important to more things than you probably know. Hell, your plasma TV wouldn't even turn on or change channels without some level of algebra. 😎

 

[P50]

What do you guys think about my approach to understanding this ?...

I tried it using "CALC", and it worked.

I looked up and down the instructions and noticed the (80x+1)x250 thing

I did a quick estimate of 80x250 and came up with 20000.

From that point, and noticing the instructions to divide by two (after twice adding the same tail end stuff) it, uh, sortta'kinda suggested the magic trick.

 

[cs217903]

FUN!!!!!

That was really cool Dan, and as for someone ruining it by doing the algebra, I'm too stupid to figure it out even by reading how it works. Not to mention that I don't have the attention span! So your village idiot sure enjoyed it!