Your Age By Eating Out

[Jade Tigress]

I just got this in an e-mail. Freaky, it works.

YOUR AGE BY DINER & RESTAURANT MATH



DON'T CHEAT BY SCROLLING DOWN FIRST!
It takes less than a minute .
Work this out as you read ...
Be sure you don't read the bottom until you've worked it out!


1. First of all, pick the number of times a week that you would like to go out to eat.
(more than once but less than 10)

2. Multiply this number by 2 (just to be bold)

3. Add 5

4. Multiply it by 50

5. If you have already had your birthday this year add 1756 .
If you haven't, add 1755.

6. Now subtract the four digit year that you were born.

You should have a three digit number

The first digit of this was your original number of
how many times you want to go out to restaurants in a week.

The next two numbers are

YOUR AGE! (Oh YES, it is!!!!!)

THIS IS THE ONLY YEAR (2006) IT WILL EVER WORK, SO SPREAD IT AROUND WHILE IT LASTS


​

 

[terryl965]

It actually works great who thought of this?

 

[MA-Caver]

It actually works great who thought of this?

Somebody with nothing to do and too much time to do it.

 

[exile]

On a vaguely related note, I discovered the following interesting fact while trying to explain some rules of thumb for multiplying to my son, who's in 4th grade: if you pick an arbitrary number n and multiply it by some arbitrary multiple of 9, the sum of the digits in the result will always be a multiple of 9, or, putting it another way, for any number m, summing the digits in the product 9m will always yield a multiple of 9.

E.g., 7x5x3 = 105; 9x105 = 945 and 9+4+5=18 = 9x2

More elaborately,

9x8x6 = 432; 432x174294 = 75,295,008; 7+5+2+9+5+0+0+8 = 36 = 9x6

and so on. I've often wondered since if it would be possible to determine the multiple of 9 in each case (2 in the first example, 6 in the second, and so on) but I have too many other pointless things I have to do first to spend any time working on this one...

 

[fnorfurfoot]

That age/eating out math trick was cool. If I was smarter at math, I would guess that the formula would be easy to figure out. Unfortunately, I'm not so I stay amazed.

 

[Hand Sword]

:erg:

It Worked!

 

[drummingman]

wow thats cool.it worked.

 

[Bigshadow]

That age/eating out math trick was cool. If I was smarter at math, I would guess that the formula would be easy to figure out. Unfortunately, I'm not so I stay amazed.

I am no math wiz but I believe they make use of prime numbers. Both 1755 and 1756 are primary numbers and concidering that everyone's birthday will fall into 19XX it further controls the results. This way it makes the behavior predictable. Encryption algorithyms often use large prime numbers for their base to work from for encrypting and decrypting keys. Since there is an infinite amount of prime numbers it makes them very hard to crack.

 

[mrhnau]

1. First of all, pick the number of times a week that you would like to go out to eat.
(more than once but less than 10)

2. Multiply this number by 2 (just to be bold)

3. Add 5

4. Multiply it by 50

5. If you have already had your birthday this year add 1756 .
If you haven't, add 1755.

6. Now subtract the four digit year that you were born.
​

Lets say X = number of times you eat out, Y = year you were born. Lets say you already had it this year.

1) You get X
2) 2*X
3) (2*X) + 5
4) 100*X + 250
5) 100*X + 2006
6) 100*X + (2006 - Y)

So, its not all that amazing really... unless you are over 100 this will work. I'm guessing there are not alot of internet savvy centerians out there though Say if you were born in 1900 you might actually get that you are 6 years old and go out one more time a week.

This is cute, but just playing w/ numbers. If you want to change it for different years, just add another number here or there to get 2007, 2008, etc. Changing step 5 to a different number would do fine.

 

[mrhnau]

On a vaguely related note, I discovered the following interesting fact while trying to explain some rules of thumb for multiplying to my son, who's in 4th grade: if you pick an arbitrary number n and multiply it by some arbitrary multiple of 9, the sum of the digits in the result will always be a multiple of 9, or, putting it another way, for any number m, summing the digits in the product 9m will always yield a multiple of 9.

E.g., 7x5x3 = 105; 9x105 = 945 and 9+4+5=18 = 9x2

More elaborately,

9x8x6 = 432; 432x174294 = 75,295,008; 7+5+2+9+5+0+0+8 = 36 = 9x6

and so on. I've often wondered since if it would be possible to determine the multiple of 9 in each case (2 in the first example, 6 in the second, and so on) but I have too many other pointless things I have to do first to spend any time working on this one...

Interesting... thats how I learned to tell if something was a multiple of 3. Works same way. I guess its kind of logical for it to work for 9, since 9 = 3*3

3*7 = 21 -> 2+1 = 3*1

9*7 = 63 = 3*(3*7) = 3*(21) -> 3*(2+1) = 6+3 = 9*1

neat

 

[exile]

Interesting... thats how I learned to tell if something was a multiple of 3. Works same way. I guess its kind of logical for it to work for 9, since 9 = 3*3

Hey, that's right!

I3*7 = 21 -> 2+1 = 3*1

9*7 = 63 = 3*(3*7) = 3*(21) -> 3*(2+1) = 6+3 = 9*1

neat

Brilliant! I started by trying to give my son some shorts cuts for multiplying certain numbers that he was having trouble with when they were used in basic multiplication, and I had noticed that 9,18, 27, 36... and 90 all sum to 9. But then I started trying it with larger and more complex products and it seemed to be holding up. It would be a fairly difficult thing to construct a full blown inductive proof of it, maybe---or maybe not; but it hadn't occurred to to work `backwards' and try it out with 3s. Sure, though, it's gotta be... very nice observation. Now all we need to do is figure out why it has to be that way, eh? :wink1:

 

[Jade Tigress]

Well ya see...I is math stoopid. You all are amazing.

 

[exile]

Well ya see...I is math stoopid. You all are amazing.

Hi Pam---no, you're not math-stoopid. I'd bet hight that you just weren't taught it well, probably. Math is really taught badly in school, I've noticed. If you'd been lucky enough to have a teacher early enough who knew it well enough him/herself to show you how to play with it, make a game out of it, you'd probably find it a piece of cake. Most people could be really good at math, I think, if their interest weren't killed off early...

 

[Bigshadow]

Hi Pam---no, you're not math-stoopid. I'd bet hight that you just weren't taught it well, probably. Math is really taught badly in school, I've noticed. If you'd been lucky enough to have a teacher early enough who knew it well enough him/herself to show you how to play with it, make a game out of it, you'd probably find it a piece of cake. Most people could be really good at math, I think, if their interest weren't killed off early...

I believe that is very true! I hated math until after high school and college. I worked for a land surveying company for a little while and that is where I found math to be exciting and fun! Then later in Civil engineering, now in software encryption. I learned more about math by applying it than in school. I am weird like that, I learn fast by applying them.

 

[shesulsa]

I don't like the last two numbers ....

 

[elder999]

I don't like the last two numbers ....

beats the alternative.

besides, it's not like you look it.:wink1:

 

[exile]

I believe that is very true! I hated math until after high school and college. I worked for a land surveying company for a little while and that is where I found math to be exciting and fun! Then later in Civil engineering, now in software encryption. I learned more about math by applying it than in school. I am weird like that, I learn fast by applying them.

This is exactly the kind of thing I had in mind---the fact is that many people who carry out certain kinds of mathematically sophisticated thinking on a daily basis because the tasks they're involved in require them to do so. They wind up `chunking' concepts together and manipulating and making deductions from the relations among those chunked concepts that they don't necessarily realize is mathematical thinking. And yet many of them think they're `bad at math', not recognizing that what they do really is mathematics... what a waste! You were luckier than these people, Bigshadow---very likely, if you'd gone in a different direction professionally, you'd still have that negative sense about math. The ability to reason in that kind of systematic and abstract way that your job brings out in you would still be there in you, but you wouldn't know it. I think an awful lot of people who think they're bad a math could probably be good, maybe very good at it, but never got the chance to engage with tasks that allowed them to use that ability.

Math teaching should recognize that many people do have talents in that direction, even though they don't realize it and though some of them are actively math-phobic. I remember, when I was in school, how quickly our teachers partitioned their math classes (in their minds, of course, but it was obvious anyway) to those with very evident talent, on the one hand, and all the other `hopeless cases' on the other. I think things are better now in at least some schools. But observing my own math teachers all through K--12, I come to the conclusion that most of them just wanted to teach to the small minority who needed no guidance whatever, or almost none, to absorb the content of the class. It was a rare teacher indeed who took extra time during the class to make things clearer to the kids who were finding it rocky. I'm convinced that many of the latter could have been just as good as the other group, but they needed to learn the material in a different way, and it wasn't a way that most of the math teachers I knew were willing to seek out...

 

[Jade Tigress]

Hi Pam---no, you're not math-stoopid. I'd bet hight that you just weren't taught it well, probably. Math is really taught badly in school, I've noticed. If you'd been lucky enough to have a teacher early enough who knew it well enough him/herself to show you how to play with it, make a game out of it, you'd probably find it a piece of cake. Most people could be really good at math, I think, if their interest weren't killed off early...

Thanks. I tried to rep ya but have to *spread it around* first.

You're right though. And not just that I was never taught it well, ( and I am not mathematically inclined to begin with) but I was actualy never taught math. How weird is that? I can barely add without a calculator.

We moved around ALOT when I was a kid. I don't recall staying in the same school for a full year until the 6th grade. The schools were never on the same schedule. So the school I was in wouldn't have taught an area yet, then we'd move mid-year and the new school would already be past it. So I would miss entire chunks of education. This was especially noticeable with math.

 

[exile]

Thanks. I tried to rep ya but have to *spread it around* first.

Well, thank you for the kind thought anyway, JT!---it just really bothers me when I hear someone assuming they're just no good at math or related kinds of thinking. A lot of kids at Ohio State have that negative sense of their own math abilities, and most of the time I have this strong sense that it's not really true, so it's kind of something I react to when I come across it...

You're right though. And not just that I was never taught it well, ( and I am not mathematically inclined to begin with) but I was actualy never taught math. How weird is that? I can barely add without a calculator.

We moved around ALOT when I was a kid. I don't recall staying in the same school for a full year until the 6th grade. The schools were never on the same schedule. So the school I was in wouldn't have taught an area yet, then we'd move mid-year and the new school would already be past it. So I would miss entire chunks of education. This was especially noticeable with math.

Yes, that would have hurt you in this, Pam, because there seems to be something about early exposure to math which makes it way easier for people to learn. A lot of people I know who are math wizards had parents who, without being mathematicians themselves, enjoyed math as a mental exercise or for its aesthetic value---the sheer beauty of some of its results. So they talked math, and played with math, with their children and showed them by example that this stuff is yet another source of pleasure in life.

But if you don't get that exposure, at home or in school, early on, it becomes much harder---much. The ability is I think still there, but it's now more like learning a second language, rather than the effortless way you learn your first language. I think as long as you're exposed to it at one point where you just gotta do it---kind of the experience Bigshadow was talking about in his post---you can still eventually get hold of it and develop it. But what happens a lot is, people who wind up feeling themselves `no good' at it learn how to avoid it, and so you get this cycle.