MATHS Help please...We're stuck on some 11+ questions

[Ingles2]

Please can someone show ds1 and myself how to work out this equation question
4n+15=45-2n
ds thinks the answer is 15,
the book says 5 and
I'm clueless how to even start...

Wot Malaleuca said. Get all of the 'n's onto one side of the equation, and the non-n's on the other. If you move (- 2n) to the other side, it becomes (+ 2n). If you move (+ 15) to the other side, it becomes (- 15).

Hence:

4n+2n = 45-15

The you can work it out easily from there!

Boris is t
Kyle is t+5
ian is 3(t+5), which is 3t+15

is anyone else quite enjoying the maths exercises?

I teach it at secondary school! But I think the simpler equations are also taught at primary

I can't post quick enough!

that was to malalueca

I teach my 5's and 6's simple algebra ( like this!) and they love it!

yes, it's one of thos topics that they do every year all the way through school, just getting more and more complicated!

Bella - I saw the Grade 7 teacher at my school showing some children the other method mentioned here, and it does make a lot more sense to children I think than mine. I had a moment of enlightenment!

OP:

You and your DS need to get secure with negative numbers and what they really mean: first in reality and then in abstract.

So when confronted by:

4n+15=45-2n

and you know that you want to "get rid of the -2n" you will automatcially know what to do and not have to "remember a trick".

Go out to the garden and dig our 2 plant posts full of soil and dump to one side.

See this as being represented by "-2n".
n = 1 pot full of soil

Now to go back to a nice flat flower bed you will need to add back the 2 pots of soil.

-2n + 2n = 0.

to clarify - the hole is "-2n"

gah may have made things worse

Thankyou so much everyone...
We're going to go through these now

Ds1 says a big Thankyou
He can't believe how quickly you all posted and says he didn't think anyone would want to help a

Many of us are teachers. we simply can't resist

ohhhh

AIBU to be really disappointed that I missed this thread?

I really need to get my act together and start tutoring

Don't you worry... I can post more.
I'll proobably need to post more
Ds1 is really good at maths but am thinking maybe we should have started some 11+ test practice before now..
especially as I'm so rubbish at it