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Yes, and if you use a mix of apples, lemons, oranges, etc. you can refer to it all as "fruit" and then go on to talk about class inheritance and so on... Brilliant!
- I would love to change the world, but they won’t give me the source code.
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Forogar wrote: es, and if you use a mix of apples, lemons, oranges, etc. you can refer to it all as "fruit" and then go on to talk about class inheritance and so on... Brilliant!
Hah! That is brilliant! I hadn't thought of that. 
Marc
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I should add, He isn't that young. He is really quite good at Science and Math. So logically speaking we weren't way off topic at all. Over 10
To err is human to really mess up you need a computer
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Does he know algebra?
What exactly would you like to explain?
Variables are an abstraction for a model that we use in math, programming and other things.
Talking about A and B allow us to think in general (abstract) terms.
I think that was astute for him to ask why not just add 2+3 together if he doesn't understand the need for the abstraction.
I agree with Mark's line of explanation, use something tangible.
To tie the entire argument together, where does the answer get stored?
If the equation is A+B=C, have a third bowl labeled C, place the bowls A and B inside of C.
How many oranges are in C.
A is still equal to 2
B is still equal to 3
C is now equal to 5
And no laws of physics had to be broken to magically produce 5 new oranges just to assign the answer to C.
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Just found where I discovered variables aged 8.. on page 58 of this[^].
How do you know so much about swallows? Well, you have to know these things when you're a king, you know.
modified 31-Aug-21 21:01pm.
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rnbergren wrote: Ideas?
Management track?
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Perhaps a DNA test ?
| "The difference between genius and stupidity is that genius has its limits." - Albert Einstein | | "As far as we know, our computer has never had an undetected error." - Weisert | | "If you are searching for perfection in others, then you seek disappointment. If you are seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010 |
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It might be time to try the Father Ted "small cow and far away cow" test.
It always gets me and if he passes it he's probably fine.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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Perhaps you should put off this sort of discussion until after his third birthday. 
Will Rogers never met me.
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Looks like he could have a bright future in customer support.
".45 ACP - because shooting twice is just silly" - JSOP, 2010
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You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
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When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013
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When you go on to constant declarations, you may pick up some hints from the famous Xerox Fortran programming manual (in Fortran, constants are defined by DATA statements), to explain the rationale behind named constants:
The primary purpose of the DATA statement is to give names to constants;
instead of referring to PI as 3.141592653589797, at every appearance,
the variable PI can be given that value with a DATA statement, and
used instead of the longer form of the constant. This also simplifies
modifying the program, should the value of PI change.
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I would get two containers and label them a and b. Bowls, boxes, etc.
Then I would say something like: Every day I am going to count the number of your toys that are in the living room. I will write that number on a slip of paper and put it in bowl a. Your Mom will count the number of toys in your room and write that number down on a slip of paper and put it in bowl b.
So everyday I want to know the total. I could say add the number in bowl a to the number in bowl b but to make things simple I say a+b which means the same thing.
bleahy
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It's a developmental thing. I could not help my son when he was in first grade. It seemed he couldn't get anything. Then at 12 he got into a spot of bother and I took him to a night class I was taking. He sat at a computer next to me and said show me some C. I opened an IDE for him and showed him a couple of things, and went to my own work for the class. After a while he said look at this, and he ran a command line program he had written that prompted the user for a password, (hard coded), and did some small thing. He had never seen C code. He's a developer now.
Take heart and let the kid grow.
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Take two paper cups and a magic marker. On one write "A"; on the other, "B". Put two beans in "A" and three beans in "B". Ask your son how many beans are in A, how many in B, and how many added together.
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Not knowing for sure how old your son is.
Algebra is the best way to explain it.
Area = WxL
Programming is about abstracting one solution to solve many problems, just like Algebra.
The other way is to use coins. You enter how many quarters, nickels and dimes you have, and it tells you how much it is worth. Again static formula. I had 2yrs of BASIC programming before I learned ASSEMBLER and Realized that a variable was just a reference to a specific memory address. It was a cool day...
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What happens in the event that figure "A" is attracted to figure "B" and wants to get married, but figure "A" is already married to, say, figure "C," and figure "B" is engaged to figure "D"? But figure "A" can't keep his hands off of figure " B," because she's got such a great figure?
from M*A*S*H episode "Dear Dad"
Brent
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Start with
2 + _ = 5
What goes in the blank?
3
What if instead of using the blank I say
2 + @ = 5
What is the value of @?
3
What if instead of using the blank I say
2 + a = 5
What is the value of a?
3
What if I say:
_ + _ = 5
or _ + @ = 5
or a + b = 5
This forms a "Fact Family"
Plot the fact family on a piece of graph paper
hooked.
If they understand negative numbers (direction or debit/credit) make sure you graph some negative numbers as well.
Then worry about computer memory and the like.
A good analogy for computer memory/nicknames
Addresses/mailboxes on a street, but you say "Bobby's House" "Sally's House" etc.
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Hmmm...the concept of variables/memory locations.
OK.
His best friend's phone number.
"671-1375" isn't his best friend, but it using it will get him his best friend.
Not a perfect analogy, but might get him pointed in the right direction.
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If you want to teach variables, don't use terrible variable names. If you example wouldn't pass a code review it isn't a good teaching example.
Also with abstract concepts relate them to something concrete.
Let PricePerTooth = $0.25
Let NumberOfLostTeeth = 4
HaulFromToothFairy = PricePerTooth * NumberOfLostTeeth
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And then... My first programming experience was with BASIC, in those days when it really was BASIC! Numeric variable names were restricted to A to Z and A0 to A9, B0 to B9 etc. up to Z0 to Z9 - 286 numeric variables, if you used them all. String variables were $A to $Z - 26 in all.
If your background is like that, statements like "Let NumberOfLostTeeth = 4" makes no sense at all. It provokes a SYNTAX ERROR message, or something of that sort.
(Sort of if you - anno 2015 - try to use non-ASCII letters or spaces in a file name on a *nix system... Yes, the underlaying file system can handle it, in principle, but nine out of ten application barf if you simply give them such a filename, plainly, with none of the seven, or is it eight, or nine, different escape/quoting alternatives, only one of which is understood by the application.)
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You're problem is that you are thinking abstract, and your son isn't. Get some physical objects and label them. Like paper cups and marbles.
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You're discussing a 'pointer to a memory address area" to a KID????
Good Lord....
Heck, I probably wouldn't discuss memory pointers during the first SEMESTER of a programming course. They are an unimportant implementation detail.
As others have pointed out, better to go with boxes drawn on a sheet of paper, or bags of candy. Talk of the concepts rather than the mechanics.
Truth,
James
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Wow, having to describe what a name is to a first-grader. Glad I dodged that bullet. I'm going to assume you wanted a straight answer to this question, so ...
The Alice-in-Wonderland answer below is an awesome answer, but is probably a bit too hard for a first grader. So you could say, "A name is a short word to describe something. We call you Bob (whatever his name is), or Bobby, or sweetie-pie, because it's faster than calling you 'skinny red-headed kid with the lopsided grin and the goofy sense of humor' all the time. Your name isn't you, it's something we say that picks you out of a crowd.
Now 'a' and 'b' are names. They name little boxes in the computer that each can hold a number. There are millions of these little boxes, so we have to give them names to pick them out of the crowd.
When we say 'let a = 2' we are saying, put the number '2' into the box whose name is 'a'. When we say 'c = a + b' we are saying, take the number out of the box named 'a', take the number out of the box named 'b', add the numbers together, and put them in the box named 'c'.
I actually had the grown-up version of this problem when first learning to program. I didn't understand the difference between symbolic constants, where the name actually meant a number, from variables, where the name meant a storage location into which you could put a number. I didn't get why the assembler (yeah, they taught programming using assemblers, what were they thinking) produced an error when I tried to assign a new value to a symbolic constant.
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rnbergren wrote: Ideas? I didn't get anywhere
It sounds like you didn't manage to connect to the concrete knowledge he knows, before you tried to extend his knowledge into something abstract. Perhaps try again, using x & y as variable names. That should make the equation "x + y" look more like something he's familiar with from algebra classes. Explain it as how the computer is computing the result of the algebraic equation.
And whatever you do, keep the how-a-computer-does-stuff talk out of any explanation. None of it is relevant to beginning programmers, and just serves to confuse and demoralize them.
We can program with only 1's, but if all you've got are zeros, you've got nothing.
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Usually when it comes to variables i use this analogy. Let any variable be a room in a file cabinet. We stick on one of them the letter a, that is our variable. We stick on another the letter b, being another variable. In the first, a room, we put the number 2. In the second one, b, we put the number 3. What would result from adding the content of a and the content of b?
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