Maths - Algebra in particular

(31 Posts)
user7755 Wed 06-Apr-16 17:50:53

DS (age 12) has just had a letter home saying that he is behind in maths and can we do activities using this particular website. No problem, he doesn't do enough study out of school and it's hard to nag him when we don't know what he should be doing (how DO people know that by the way?)

Anyway, we start looking at algebra and it has totally changed since I was at school. There are symbols that i have never seen in my life, I work out an equation in the way I was taught and it comes up as wrong (I learned about BODMAS the other day too, which is completely the opposite to how we were taught). Have now contacted maths tutors but my question is really - WTAF? Surely the rules of mathematics can't have changed in the last 25 years? And can anyone recommend any basic maths texts?

I consider myself to be fairly intelligent (have trained to MSc level and am now lecturer) but this has blown my mind!

noblegiraffe Wed 06-Apr-16 17:54:43

Nothing has changed in the last 25 years in terms of symbols/rules as far as I'm aware (maths teacher with maths degree). What symbols do you mean? Perhaps you are misremembering methods?

This website is excellent for videos explaining the current maths curriculum:

mathswebsite.com

user7755 Wed 06-Apr-16 18:05:06

Thank you, will have a look at that. The symbol looks like an apostrophe - never seen in in the context of maths though confused

My recollection was that, for example...

2(n+5) means that you calculate what n+5 is and then multiply the result by 2. Whereas this came back as wrong. Have I been doing it wrong all these years?

AppleSetsSail Wed 06-Apr-16 18:05:50

Also, check out Khan Academy.

Nothing has changed but unless you use a lot of maths for your work, you'll need to re-learn a few things. It shouldn't take you more than a few hours to get the hang of it.

AppleSetsSail Wed 06-Apr-16 18:06:13

Nope, it's 2n + 10

AppleSetsSail Wed 06-Apr-16 18:07:27

Sorry - not wrong, but you'd approach it as 2n + 10

user7755 Wed 06-Apr-16 18:11:37

Lord alive! This is like the time that I realised that I have been spelling Lily wrong all my life!

I got an A for GCSE too - I think I need to sit in on the maths tutor lessons.

Thank you, this is what is great about mumsnet

noblegiraffe Wed 06-Apr-16 18:14:13

The apostrophe symbol, like A' ?
Is that in the context of Venn diagrams?

tiggytape Wed 06-Apr-16 18:15:33

Is the apostrophe the recurring sign? We used to do it as a tiny dot just to the top right of the number but I notice DS draws it as an apostrophe directly above the number (I have just looked it up and appears we are both doing it wrong though as it is supposed to look like a little dot directly above the number)

user7755 Wed 06-Apr-16 18:25:40

Looks like this 3'n'n

PolkadotsAndMoonbeams Wed 06-Apr-16 18:27:22

Apostrophes can also be used if something's the same but different (so if you had two triangles the sides on one could be marked a, b, c and the equivalent sides on the other a', b', c').

2(n+5) and 2n+10 are the same - just multiplied out. Can you give us an example of a question please?

user7755 Wed 06-Apr-16 18:28:58

The idea is that its a memory / matching game. You have to find the tile which means the same thing. So all I have to go on is 3'n'n

PolkadotsAndMoonbeams Wed 06-Apr-16 18:29:03

Ah I bet that's a * - means to multiply.

So that's the same as three n squared (longhand!).

zoelife111 Wed 06-Apr-16 18:29:57

If it is any consolation, I am a science teacher, and haven't been able to make any sense of my kids maths homework since primary school!

user7755 Wed 06-Apr-16 18:30:12

Right, am going to try it now....

noblegiraffe Wed 06-Apr-16 18:30:30

Can you post a screenshot of the matching game? I haven't the faintest idea what the apostrophe sign is meant to mean there.

PolkadotsAndMoonbeams Wed 06-Apr-16 18:30:37

So you're right - they're different because they're the computer symbols, rather than by hand.

So:

* = multiply
/ = divide
X^2 = x squared
X^3 = x cubed

user7755 Wed 06-Apr-16 18:31:37

The answer was 3n squared. There is another one...n'n - so by that logic is the answer n squared

PolkadotsAndMoonbeams Wed 06-Apr-16 18:33:05

I would think so smile

If you wrote it as n x n you could get it then grin

noblegiraffe Wed 06-Apr-16 18:34:01

OK, 3 x n x n = 3n^2

The apostrophe is not used in maths to mean multiply. This is not a new maths symbol, this is either a font not showing correctly, or a matching game being written incorrectly.

user7755 Wed 06-Apr-16 18:37:41

Thank you all. Am going to try to finish it myself now!

user7755 Wed 06-Apr-16 18:39:44

Did it! Just those two things made a big difference - daren't drag DS down to do it again tonight after spending so long trying to work it out earlier but at least we have something to work on for tomorrow

MadamDeathstare Wed 06-Apr-16 18:41:13

I used a mathbff video on Youtube so show me how to 'complete the square' to solve quadratic equations (I was never taught this method in school, we just used the quadratic formula). I found that the MIT grad. who narrates the video goes slowly and clearly through each step so it is easy to keep up. I'm going to be using her videos for some of the higher level math that is no doubt headed my way.

The symbols haven't changed as far as my DC are concerned, but there are methods for solving problems that were never covered when I was at school. They are specifically told to use those methods and if they are confused about how they work, obviously it is an exercise in futility for them to try and explain them to me.

MadamDeathstare Wed 06-Apr-16 18:42:05

Sorry, here is a link to one of her videos www.youtube.com/watch?v=ZIwmZ9m0byI

user7755 Wed 06-Apr-16 18:50:35

Thank you madam - this thread began as a semi rant but has been so useful!

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