Member Photos

[brewer]

I don't know... you're not having me try and solve for a letter. That's all numbers so I would think it's pretty straightforward. 

However, is that 4 portions 1/2 cup each or is the total of the four portions equaling 1/2 cup.

If you need 1/2 cup of butter for 4 portions how many cups of butter do you need for 6 portions?

Two people who don't get to eat?

[pocaracas]

Yeah, like Kernel said, I don't think it's about being smart or anything... maths is just a set of rules, with its own language set. It's more similar to learning/knowing a different language, than being smart.
Most of the times, it's about remembering the right words to make the full sentence.... there are so many words... so many.

Anyway, letters in maths should not be feared. They simply represent a number. They may represent a number we wish to discover, or any arbitrary number we may wish to assign.
The letters are like labels for numbers, when we are not sure which numbers should go in there. Even when we do know the numbers, they tend to be so weird that we prefer to use a letter in it's place, like the speed of light in vacuum, 'c' = 299 792 458 m s-1, or the famous π=3.141592653589793238462643383279...

So, anyway... I had to look up what this "foil" business was, because in Portuguese there's no such thing
a*(b+c) = a*b + a*c... simple enough, but if a itself is a sum
(a1+a2)*(b+c) = a1*b+a1*c + a2*b + a2*c, that's cool.... how about we add some more terms?

(a1+a2+a3)*(b+c) = a1*b+a1*c + a2*b+a2*c + a3*b+a3*c, just keep doing more of the same!

Red mine. 

You had me clear up to that point. Then you lost me.

Gotcha... let's try with numbers, then!

3*(9 + 5) = ???

Because we have those parenthesis in there, we are saying that whatever is inside them must be calculated before what comes on the outside - this is part of the language I mentioned.
So that becomes:
3*14 = 42.

But that's the same as splitting the multiplication in two a*(b+c)= a*b + a*c:
3*9 + 3*5 = 27 + 15 = 42

and is substantially different from

3*9 + 5 = 27 + 5 = 33

The parenthesis make a difference in the order of the calculations.
As a general rule, multiplications and division are carried out before sums and subtractions. The parenthesis force us to carry out whatever is inside them first, regardless of the operators on the outside.
You can have enclosed expressions in parenthesis inside parenthesis. When that happens, you should process the innermost one first, and then work all the way to the outermost one.
For example:
3*(9*(4+2)+5) =
= 3 * ( 9*6 + 5) = { or   3 * (9*4 + 9*2 + 5)  = 3 * (36 + 18 + 5) }
= 3 * (54 + 5) =  {Note how the multiplication got calculated first, inside the parenthesis - general rule applies for each expression}
= 3 * 59 =
= 177

[Whateverist]

She threw this at me:

(E+2)(E+2)

I never was good in math. Because of this, I didn't have to learn algebra. I'm 46. She's trying to teach me how to use something that in 46 years of my being on this earth, I've never needed.

She tried teaching me how to foil. The only thing I remotely know about foiling has to do with a hair color technique and you don't need algebra for that!

So...kudos to everyone who is smart enough to understand it. I don't think I ever will.

I like your daughter.  Try this: experiment with multiplying 12 by 11 which should come out as 132.


Can we split one of them up as a sum?  11 = 10 + 1

12(10 + 1) So will twelve 10's and twelve 1's give the same result as twelve 11's?

12(10) = 120  and  12(1) = 12  and  120 + 12 = 132  [Yup, good so far.]


What about if we also split the 12 up into the sum of 10 and 2, while still leaving 11 expressed as the sum of 10 and 1?

(10 + 2)(10+ 1)  We'll follow the same plan of attack, but use (10 + 2) 10's and (10 + 2) 1's.

(10 + 2)10  and  (10 + 2)1  Since order is irrelevant for multiplication we'll write it as 

10(10 + 2) and 1(10 + 2)  So we need ten 10's, ten 2's, one 10, and one 2 = 100 + 20 + 10 + 2 = 132  [Still good.]


We just 'F.O.I.L.'ed (10 + 2) and (10 + 1).  F.O.I.L. actually becomes useful when some of the numbers are variables, you know, the dreaded letters representing an as yet unknown number.

Okay, I'll stop now.

---

Doh! This is what happens when I don't read all the posts after a post I want to respond to. Poca, you ninja!

Red mine. 

You had me clear up to that point. Then you lost me.

Gotcha... let's try with numbers, then!

3*(9 + 5) = ???

Because we have those parenthesis in there, we are saying that whatever is inside them must be calculated before what comes on the outside - this is part of the language I mentioned.
So that becomes:
3*14 = 42.

But that's the same as splitting the multiplication in two a*(b+c)= a*b + a*c:
3*9 + 3*5 = 27 + 15 = 42

and is substantially different from

3*9 + 5 = 27 + 5 = 33

The parenthesis make a difference in the order of the calculations.
As a general rule, multiplications and division are carried out before sums and subtractions. The parenthesis force us to carry out whatever is inside them first, regardless of the operators on the outside.
You can have enclosed expressions in parenthesis inside parenthesis. When that happens, you should process the innermost one first, and then work all the way to the outermost one.
For example:
3*(9*(4+2)+5) =
= 3 * ( 9*6 + 5) = { or   3 * (9*4 + 9*2 + 5)  = 3 * (36 + 18 + 5) }
= 3 * (54 + 5) =  {Note how the multiplication got calculated first, inside the parenthesis - general rule applies for each expression}
= 3 * 59 =
= 177

[pocaracas]

Doh!  This is what happens when I don't read all the posts after a post I want to respond to.  Poca, you ninja!

I like how you worked up to it, better!

Nothing like a real maths teacher!

[brewer]

I keep forgetting which finger I'm on and have to start all over.

[pocaracas]

I keep forgetting which finger I'm on and have to start all over.

You can take it a finger further, if you include your toilet bits


Also, binary finger counting can get you up to 31 on one hand. (1023 on 2 hands!)
just remember to be careful with Number 4, 5, 16 and 18.

---

---

[LadyForCamus]

I keep forgetting which finger I'm on and have to start all over.

You can take it a finger further, if you include your toilet bits

That's what she said.

[Clueless Morgan]

I love how the "post your photos!" thread has become an algebra tutorial thread now.

That's what she said.

[pocaracas]

[Joods]

Yup. Because all of that hurt my damn head.