The Student Room Group
Could you give more details over the coursework. I'm not familiar with the title, but might be able to help if you say more what it's about.
Reply 2
Roger Kirk
Could you give more details over the coursework. I'm not familiar with the title, but might be able to help if you say more what it's about.

Yeah sure:

"Looking at this T-shape drawn on a 9 by 9 number grid- the total of numbers inside the T-shape is 1 + 2 +3 + 11 + 20 = 37. This is called the T-total. The number at the bottom of the T-shape is called the T-number. The T-number for this shape is 20. Investigate the relationship between T-total and the T-number" I'm currently investigating the relationship between 'T' (T-total) and 'n' (T-number) in terms of 'n'.
Right, thanks.

(Never hear of this course work before...sounds interesting).

So you start by labelling a general t-shape with the values of each number in terms of n.

The bottom on is n, like you say.

The one above that is n-9

The the top of the t-shape has entries n-17, n-18 and n-19.

Add these up an you get the total for the sum of the numbers in any general t-shape on the 9x9 grid as being 5n-63

Hope that helps.
Reply 4
Roger Kirk
Right, thanks.

(Never hear of this course work before...sounds interesting).

So you start by labelling a general t-shape with the values of each number in terms of n.

The bottom on is n, like you say.

The one above that is n-9

The the top of the t-shape has entries n-17, n-18 and n-19.

Add these up an you get the total for the sum of the numbers in any general t-shape on the 9x9 grid as being 5n-63

Hope that helps.

Yeah that does help, but are there any other techniques to finding this nth term?
DiageoLiam
Yeah that does help, but are there any other techniques to finding this nth term?

What do you mean?

That is the best, easiest way.

In your coursework you'd be expected to find some totals for different positioned t-shapes, then have a go a generalising the out come, maybe predicting the total for another few t-shapes. You could generate a sequence starting with n=20, then n=21, n=22, n=23 up to the highest n you can fit on in that row and find the nth term of that sequence using the usual method of looking at differences.

Fromthere you coul check your predictions and try generalise the result to show the nth term is true for any t-shape by doing what I did above.

To get decent marks you'd then need to extend the work to differnet problems. Do at least one of these: look at differnet shapes, different sized t-shapes, different sized grids. You'd need to exactly the same for at least one of these changes. It may even be possible to try and fin a general formula for the each problem using two-variable instead of just n (eg for the total sum of numbers in a t-shape with t-number n in an m by m grid).

For really top marks youd have to introduce some math which is not part of your GCSE course...this is where Ii'm stuck right now on how to advise you. I can't think what you could do right now.
Reply 6
Roger Kirk
What do you mean?

That is the best, easiest way.

In your coursework you'd be expected to find some totals for different positioned t-shapes, then have a go a generalising the out come, maybe predicting the total for another few t-shapes. You could generate a sequence starting with n=20, then n=21, n=22, n=23 up to the highest n you can fit on in that row and find the nth term of that sequence using the usual method of looking at differences.

Fromthere you coul check your predictions and try generalise the result to show the nth term is true for any t-shape by doing what I did above.

To get decent marks you'd then need to extend the work to differnet problems. Do at least one of these: look at differnet shapes, different sized t-shapes, different sized grids. You'd need to exactly the same for at least one of these changes. It may even be possible to try and fin a general formula for the each problem using two-variable instead of just n (eg for the total sum of numbers in a t-shape with t-number n in an m by m grid).

For really top marks youd have to introduce some math which is not part of your GCSE course...this is where Ii'm stuck right now on how to advise you. I can't think what you could do right now.

I have already generated a G by G nth term that works fine, I'm going to investigate the relationships between n and T when the T-shape is rotated and resized.
Is this okay, or would I need to extend/explain?

n-19 + n-18 + n-17 + n-9 + n = 5n-63

The above diagram and calculation verifies that my nth term is correct and applied to all 9 by 9 grids.
That all sounds good make sure you mention the 9x9 grid is a numbere from b to b+80 an not a 9x9 grid lifted off a larger grid....if you don't understand me here don't worry....just leave it.

Can I ask what grade you are aiming for, as this will tell me how far you need to take the course work/whether you need the last part with 'new' maths or not.
Reply 8
Roger Kirk
That all sounds good make sure you mention the 9x9 grid is a numbere from b to b+80 an not a 9x9 grid lifted off a larger grid....if you don't understand me here don't worry....just leave it.

Can I ask what grade you are aiming for, as this will tell me how far you need to take the course work/whether you need the last part with 'new' maths or not.

I'm predicted an A but I'd like to aim for A*. I get confused with coursework, I can do it fine when I'm in the school enviroment but when I take it home to redraft my mind just goes blank.
In my notes I have the following calculations:

5 x 20 – 63 = 37
5 x 21 – 63 = 42
5 x 22 – 63 = 47
5 x 29 – 63 = 82
5 x 38 – 63 = 127
5 x 47 – 63 = 172


The calculations are used to express the nth term but I'm unsure as to what I should be writing about them- I surely can't just insert the calculations. Could you explain a bit more about the b to b+80 grid please?
Thanks :smile:
DiageoLiam
I'm predicted an A but I'd like to aim for A*. I get confused with coursework, I can do it fine when I'm in the school enviroment but when I take it home to redraft my mind just goes blank.
In my notes I have the following calculations:

5 x 20 63 = 37
5 x 21 63 = 42
5 x 22 63 = 47
5 x 29 63 = 82
5 x 38 63 = 127
5 x 47 63 = 172


The calculations are used to express the nth term but I'm unsure as to what I should be writing about them- I surely can't just insert the calculations. Could you explain a bit more about the b to b+80 grid please?
Thanks :smile:

Your calculations are using your forumla to work out the total of certain t-shapes.

You can check your claculation against adding up the actual numbers in those t-shapes.

As for the b to b+80 grid...

...well you started off with the grid with numbers 1 to 81 (1 = b, 81 = b+80)

You could start with any 9x9 grid with 81 consecutive numbers (eg if the first number was 50, your b to b+8 would be 50 to 130.

This is opposed to taking a 9x9 grid from a larger number grid for example, ig you were to pick a 4x4 gri from a 10 x 10 grid you could have the following to draw your grid on

3 4 5 6
13 14 15 16
23 24 25 25
33 34 35 36

Which would get you very different answer :smile:
Reply 10
Roger Kirk
Your calculations are using your forumla to work out the total of certain t-shapes.

You can check your claculation against adding up the actual numbers in those t-shapes.

As for the b to b+80 grid...

...well you started off with the grid with numbers 1 to 81 (1 = b, 81 = b+80)

You could start with any 9x9 grid with 81 consecutive numbers (eg if the first number was 50, your b to b+8 would be 50 to 130.

This is opposed to taking a 9x9 grid from a larger number grid for example, ig you were to pick a 4x4 gri from a 10 x 10 grid you could have the following to draw your grid on

3 4 5 6
13 14 15 16
23 24 25 25
33 34 35 36

Which would get you very different answer :smile:

I don't understand the b+8 part, surely if b is 50 then b+8 should be 58, not 130? How did you get 130?
Would I launch an additional investigation regarding the b to b+x?
Reply 11
..?
Reply 12
It was a typo i believe, meant to be b + 80, hence 50 + 80 = 130
Reply 13
i have the generic formula 5n-7x, x being the grid size e.g.
5x20=100 7x9=63
100-63=37
where does 7 come from?
pete15
i have the generic formula 5n-7x, x being the grid size e.g.
5x20=100 7x9=63
100-63=37
where does 7 come from?

First of all, how did you get to the generic forumla (which I am assuming is for any start value 'n' in a x by x grid).

Tell me how you derived it and I'll be better able to show you more about it as I'll know from which direction you are looking at this problem :smile:
Reply 15
the formula for a 9x9 grid is 5n-63
for a 8x8 grid it is 5n-56
for a 7x7 it is 5n-49
each time the number after 5n is going up by 7
7 times 8 (8x8) equals 56, therefore y=5n-7x
n is the t-number
y is the t-total
OK - great.

Now look at the difference between the numbers in a t-shape in consective grid sizes:


eg in a 9x9 grid you have n, n-9, n-17, n-18 and n-19

and in a8x8 grid you have n, n-8, n-15, n-16 and n-17.

Look at the number parts - what do you notice about the cumulative difference between the numbers in all terms.

Now compare the numbers in the t-shape ina 8by8 and 7by7 grid..what is the cumulative difference? Do the same for other grids. What is the differnece between them?

Do you get where the 7 comes from now? :smile:
Reply 17
i know they change each time by 7, but why 7, there must be some reason it's 7 each time
also rotated 90 degrees the formula for any rid size is 5n+7, why 7?
pete15
i know they change each time by 7, but why 7, there must be some reason it's 7 each time

Indeed there is.

By reducing the grid size by one all numbers on the row above the row cotnain 'n' are 1 number closer to 'n' and all numbers on the row above that are 2 numbers closer to 'n'.

We have 1 number (difference of 1) on the row above n and 3 on the row above that (differnece of 6 in total). So the over all difference will be 1 + 6 =7.
Reply 19
thankyou very much for finishing my maths coursework for me, in return i will try to be an active user.thanks again.