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Yes, normally I agree absolutely with that - and perhaps that is what is motivating me now.

But sometimes I just can't find the beginning of the thread of reasoning. It is as tho some pages have been left out of a book and I'm trying to make sense of the pages that I DO have.

For example. This is one of the info sites I referred to this morning. I've highlighted the bits that utterly confused me.

Double-you3.purplemath.com/modules/absolute.htm

The absolute value of x, denoted "| x |" (and which is read as "the absolute value of x"), is the distance of x from zero.

This is why absolute value is never negative;absolute value only asks "how far?", not "in which direction?" This means not only that | 3 | = 3, because 3 is three units to the right of zero, but also that | 3 | = 3, because 3 is three units to the left of zero.

But a few lines further on it says,

It is important to note that the absolute value bars do NOT work in the same way as do parentheses. Whereas (3) = +3, this is NOT how it works for absolute value:

Simplify | 3 |.

Given | 3 |, I first handle the absolute value part, taking the positive and converting the absolute value bars to parentheses:| 3 | = (+3)

Now I can take the negative through the parentheses:

| 3 | = (3) = 3

As this illustrates, if you take the negative of an absolute value, you will get a negative number for your answer.

Huh?!

Margarita

**MargaritaMc**- Replies: 4

As I said back in my introduction, I am at a basic level in maths and don't have access to a tutor.

There is masses of info on the web, but I'm discovering that I am sometimes dropped into a topic that I haven't had the lead-up to.

Today that was 'absolute values', on Khan Academy.

I found an explanation of what this is on the Maths is Fun site, by using Google, but really feel quite stressed-out at this hit-and- miss way that I am staggering around maths learning.

Can anyone recommend a list of topic areas to cover IN ORDER?

This would need to be right from basic-basics, just so that I can check the foundations before I try to move on.

I've just bought 'Basic Maths for Dummies' by Colin Beveridge, so it may help.

But - I would REALLY appreciate some advice on the order in which I would best tackle topics.

Margarita

Thank you again, Bob. Yes, the ideas are easier than the names!

I was doing the exercises at the mathopolis link where they ask you to click on which law was in operation for a given equation. I knew what the equations were ** doing ** but I kept getting the name wrong!

Margarita

**MargaritaMc**- Replies: 2

I find myself getting stuck on the NAMES 'commutative', 'distributative' and 'associative' - they are introduced in the Kindergarten level at the website...

Has anyone got a mnemonic for remembering them?

Margarita

bob bundy wrote:

You're welcome.And thanks for a really enthusiastic reply. Sometimes my posts disappear into the internet void and I never hear again from the original poster. It will be a pleasure to help you whenever I can.

Bob

You don't know what you may be letting yourself in for!

Oh yes, and I know about what it is like carefully to answer a newcomer's post - only for them never to be heard of again... My only other forum is on astronomy, and that is a great attractor of casuals.

Margarita

THANK YOU * SO* much!

My husband wondered what on earth had made me so bubbly after I'd checked my email - the sense of glee when one ** understands ** something that had been frustrating and opaque is totally delightful!

I played with the balance at the maths is fun website for ages. It is a great help to be able to visualise it like that.

Although I had seen that there were some interactive parts to the site, I usually access the web via a tablet PC running Android, which can't handle Java or Flash. My laptop runs Ubuntu, so could run the flash application but, sadly, not the Java one on the other site.

I very much appreciate your help - and your moral support. I will not be so tentative in seeking help here in future!

Margarita

PS. I do like the quote from Galileo Galilei. A splendid maxim for a teacher.

bob bundy wrote:

hi Margarita

Welcome to the forum.

Have you learnt about the factorial function yet?64! = 64 x 63 x 62 x 61 x 60 x .......x 3 x 2 x 1

...

Post your questions ... we'll be happy to help.

Bob

Thank you for your welcomes!

Bob - not only have I not learnt factorial function yet, I have never even ** heard ** of it! Perhaps I should also explain that I don't have a teacher (I've retired to a Spanish speaking island and know enough Spanish to do the shipping, but NOT enough to learn maths in!)

No, really, that is why I am so nervous at being on this forum - I'm not at all sure that you will be able to BELIEVE how little I know.

An example is worth a thousand words, and this is what I am stuck on at present. It is a question at Mathopolis described as a Pre- algebra, Year Four (hard). I can work it out intuitively, but don't know how to work it out (evaluate? Derive? Solve?) using mathematical reasoning.

Which value of n makes the sentence 6+n=4*n true?

The options are given as 4, 3, 2, or 1.

The answer is obviously n=2

BUT I can't see how I could do that formally.

Nor how I would prove (should I be asked) that n=2 is the ONLY value for n that makes this sentence true.

I've gone through the notes that I've made from the pre- algebra sections on the Math is Fun website, and can't find anything to give me guidance.

I feel that there ought to be a way to get n on one side of the equals sign and the numbers on the other, but anything that I've tried has yielded rubbish. (e.g deducting n from both sides, which gave

6+n-n= (4*n )-n. Which l looks like garbage!

Help???

Margarita

**MargaritaMc**- Replies: 15

Hello everybody, my name is Margarita and I suspect that I will be the oldest person on this forum - I am 64!

But I am extremely immature when it comes to Maths, which is why I have just begun to work my way through the Math is Fun site and have plucked up the courage to join this forum,

The reason that I am so ignorant in maths is not because I didn't pay attention when I was at school. It is simply that, mostly, I did not GO to school. I had severe polio as a baby and spent most of my childhood in hospital, where there was very little schooling. My mother taught me to read and to do simple arithmetic and I was able to teach myself a lot from reading. (I even went to university to study politics!) But I wasn't able to teach myself maths.

Now, I feel that I want to rectify that lack.

If I could ask some extremely basic questions sometimes, that would be wonderful.

With best wishes

Margarita

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