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#26 Re: Help Me ! » On a multi-part question when do you round to significant figure? » 2014-02-01 15:30:53
thanks for the links bobbym its appreciated.....
#27 Help Me ! » On a multi-part question when do you round to significant figure? » 2014-02-01 08:59:57
- silverpuma
- Replies: 5
Hi folks, I have a question to do that has a few parts but it states the answer is given to 3 significant figures. I can do all the calculations but am wondering about the 3 significant figures (which I understand how to do as well). The answer must be given in m^2
I'm given a square lawn 30m x 60m and inside the square lawn are 4 round paved areas, 2 have dia of 1.9m, one a dia of 2.2m and one a dia of 0.9m.
Do I do all my working out of all the circle areas, adding them together and subtracting from the 180 (area of lawn) and only when I get that final figure of do I consider the 3 significant figures?
Its just for example the circle with a dia of 0.9m works out at
0.6361725124 m^2 as Im working through the question and the other circles do I need to use the 10 digits after the decimal point or because I know I'm working towards 3 s.f. can I just use say 4 digits after the decimal point?
Hope Im making sense........thanks for your patience:)
#28 Re: Help Me ! » Help with grasping better problems with negative nymbers » 2013-12-18 19:47:06
Bod, hope its OK to post a link but is this the book you mentioned? Its just there seem to be so many variations to choose from I want to make sure I get the right one.
http://www.amazon.co.uk/GCSE-Mathematics-Edexcel-2010-Student/dp/1846900832
How do you post a live link here. Usually I see a "link" button?
Thanks..................
#29 Re: Help Me ! » Help with grasping better problems with negative nymbers » 2013-12-18 19:28:53
Thanks Bob for this info and recommendation and I think I'll buy myself a secondhand copy as a gift to myself for Christmas. Some light bedtime reading...............is that sad or what......
#30 Re: Help Me ! » Help with grasping better problems with negative nymbers » 2013-12-17 23:24:40
Hi;
PS: I love reading along side the forum and web is there a book on Learning maths you could recommend for me.
I have covered hundreds, sometimes emptying out massive shelves of books in the University library. I have never really found anything easier than the MIF pages right over here. I truly mean that. I suggest you keep going through them and copying them.
Books are fine but nothing beats the web for learning. If I would have had the internet and access to this forum when I was just starting out I would be much further along. That is not hype, I am serious. The opportunity to come in and ask a question and get an immediate answer is fantastic. I had to wait years before I found answers to many questions.
Try to go at your own pace. It is much better to know a handful of techniques or concepts thoroughly then to have a smattering of a lot of them.
I mean this genuinely and no false flattery the MIF site and this forum is my first place to call on when I want to learn a new section on my maths adventure. I love the concise and clear teaching and as you mentioned the help on the forum only accentuate these positives. There may be other more visually slick sites but the content is king in my book.
It amazes me sometimes how the obvious passes me by so often. I discover my blind-spots continuously....! Why didn't I think of copying and printing out the material on the MIF site as you say? Ebay here I come for a batch of cheap ink cartridges......he he.
#31 Re: Help Me ! » Help with grasping better problems with negative nymbers » 2013-12-17 22:26:13
Ahhhh the.... "brackets"...... thanks guys! This makes all much clearer. I don't like to move on to another level or section if I'm not comfortable with a question so this is great to receive the help . Simple when you know how ...:-)
@bobbym I have found probabilities perhaps the most difficult to get my head around. But the individual part I've found the hardest so far to feel I grasped fully was the "why does multiplying two negs make a pos". I could follow the rules on the same and different signs ok so could get the right answer (most of the time...!!) but understanding "why" this was so, I found difficult for a while. The balloons example on the mathsidfun site and the: quote:
Example: You owe 3 people $5 each. So you are "Negative 15" (3 × -$5 = -$15).
They then say "we like you so much we forgive the debt" ... you have just had 3 subtractions of -5, so it is like you have added $15 (-3 × -$5 = +$15)."
Was the help I needed to "get" this infused in my bones.......................thanks again guys
PS: I love reading along side the forum and web is there a book on Learning maths you could recommend for me. I'm basically learning with my son as he goes through his Maths lessons trying to keep a little ahead so I can help as best I can. He is year 9 so 2nd year at grammer school and he and I need to arrive at as high a GCSE standard as we can. I mentioned before that his teacher is first class and gives out a small booklet for each term with examples etc that is very well produced and a picture of concise information but I'd like a book to supplement this as I enjoy the learning process.
#32 Help Me ! » Help with grasping better problems with negative nymbers » 2013-12-17 19:46:37
- silverpuma
- Replies: 10
Hi all, I'm at Probabilities in my journey and have understood this section on Mathsisfun http://www.mathsisfun.com/multiplying-negatives.html So I have a reasonably good grasp of things so far. But one aspect that I can't see a section on in Mathsidfun and this idea is hurting my wee 1.5 cell brains is things like:
6^2 = 6 x 6= 36
(-6)^2 = -6 x (-6) = 36 (the 2 - negs make a pos)
These 2 examples above I can understand but the next 2 I'm not as clear on, especially the next one.
-6^2 = -36 (I thought that would be -6 x -6 = 36)
(-6)^2 = 36
I know this question is a bit confused but that's because I am a bit confused ....:-) I really need a link to a page that will spell this out for me so I can understand "why" 3rd above is -36 and not 36 as I would have thought.........................thanks for the hand holding and patience!
PS how can I type x squared instead of using the ^ symbol. I notice often you guys used a grayed out image type of text?
#33 Re: Help Me ! » Bob and others could you take a look at this question » 2013-12-10 07:32:30
It will be okay as long as there are no harsh words. It's better to do it now then to let all the students including your son learn math wrong.
Thanks again guys and..... there will be no harsh words. I'm really thankful for my son's teacher and I know he want's the best for him and has a very good reputation for producing accomplished maths students. This is just a couple of slip-ups i think due to pressure of work. Also this was homework and I suppose I would be more concerned if it was exams or structured tests etc.
#34 Re: Help Me ! » Bob and others could you take a look at this question » 2013-12-10 05:24:51
Thanks guys and yes I think we will speak with his teacher when we are having the term review one to one meeting just after Christmas..................not looking forward to this though
#35 Help Me ! » Bob and others could you take a look at this question » 2013-12-09 19:29:36
- silverpuma
- Replies: 6
I have checked this a few times and I can't understand why these 3 answers are marked wrong (hence the red X after the blue answers) The red writing below are the correct answers gave to my son but I can't get them to work. I'm confused?
I saw in the question it states that "there are several possibilities" and perhaps my son's was not one of the popular ones so it was assumed his was wrong by mistake? Any ideas.......thanks
#36 Re: Help Me ! » Teacher marks answer wrong but I cannot understand why? » 2013-12-09 15:22:06
Once again Bob thanks for your measured and thoughtful answer. My son would not like to query this error he is on the shy end of things and I'm not a very confident person myself regarding anything academic being a secondary school student with at best between a C and C+ average. But I will eagerly take up your advice and pepper you and the good folks here as and when I need some clarification. My son seems to have a natural touch (combined with hard work and a desire to get every question right) with numbers, although I do not, nevertheless I'm enjoying the journey alongside him encouraging him and discovering a road I never thought I could be or would be interested in.....Maths.
I'm smiling as I write as I think back 43 years ago, opening my 11+ results envelope on a Saturday morning, reading I failed and then without a hint of distress went back up to my bed for a few more hours sleep. Ah well, if only adult life could be lived in a free, stressless "take it in your stride" like I had all those years ago. I can dream...:-)
There are a few questions from a few weeks ago that may fall into the same category as the one we have been looking at but it may be me mistaking this time. I'll post them when I search them out. Thanks......
#37 Re: Help Me ! » Teacher marks answer wrong but I cannot understand why? » 2013-12-09 08:23:43
Bob, thank you so much for the detailed answer and it's good to know my son understood and answered the question correctly.
You are correct about question (a) I made a typo copying my son's answer, 7,0 is the correct answer.
The teacher is really excellent (strict and that's no bad thing today:-)) so this is in no way a slight on the teacher at all. Teachers are under so much pressure with result league tables etc I have a lot of sympathy for them and mistakes happen. My middle name I think is "Mistake" I am so prone to silly slip-ups myself sometimes.....LOL
Thanks again for your help.....
#38 Re: Help Me ! » Teacher marks answer wrong but I cannot understand why? » 2013-12-09 06:54:45
The missing image.....:-)
#39 Help Me ! » Teacher marks answer wrong but I cannot understand why? » 2013-12-09 06:44:40
- silverpuma
- Replies: 5
Below is the group of questions on "Transformations" my son (and me with him) is learning you will see part (c) is marked wrong. Thats not a problem, mistakes is how we learn its just I'm so daft I can't understand why we are wrong and I want to understand, please help.
(a) What translation has taken K to K in the diagram below?
My Sons Answer:
..7, 6
..marked correct
(b) What translation has taken V to V in the diagram below?
My Sons Answer:
..5, -5
..marked correct
(c) What two individual translations parallel to the x-axis and the y-axis respectively would replace the single translation from V to V?
My Sons answer:
.5,0 and then 0,-5
..marked wrong
The teachers answer is Translation y = x
PS: Im learning Maths alongside my son to try to help him I find maths really interesting and love this new learning curve for me but it does not come easy as I have no, zero, academic qualifications just lots of uneducated enthusiasm so please go easy on me .:-)
#40 Help Me ! » Is this correct? » 2011-07-14 09:32:58
- silverpuma
- Replies: 1
Anther one for checking.
Got them all right except the Kite and I got
c = 104
d= 80 the book got 72
I think this time I am right but these typos have me doubting even my adding and subtracting. Thanks for taking the time to help...........
#41 Re: Help Me ! » Polygon angles question to check » 2011-07-12 09:45:22
Good point Bobbym. I had not thought about doing that and it makes sense, I like it!!!
#42 Re: Help Me ! » Polygon angles question to check » 2011-07-12 09:26:51
.
.
No I checked this very carefully before I sent it in to the forum as I thougth initially I have perhaps taken down the wrong numbers myself in my own working out. They are 100% correct. So the mistake is in the book, I'm glad I thought I was just being really daft..................it happens................
Thanks for taking the time to help...........
#43 Help Me ! » Polygon angles question to check » 2011-07-12 05:26:34
- silverpuma
- Replies: 5
Hi all, I have another question to check where I can't get the books answer.
Question:
Five of the in a hexagon are 130, 102, 105, 97 and 103. Find the size of the sixth angle.
I did the following:
180 x (n-2)
180 x 4 = 720
720 - 130 + 102 + 105 + 97 + 103
720 - 537
183
Book says 173
I could be doing the same mistake over and over and need a fresh pair of eyes to see my daft moment LOL
#44 Re: Help Me ! » question to check - decimals dot notation » 2011-07-05 03:48:11
Hi;
Your welcome! Just for the record, what is the name of this book?
Ccea-Foundation-Mathematics-Rosie-McCrae I tried to send the amazon link but was blocked.
I am really enjoying the book a full 630 pages with loads of test questions. The answers (another 105 pages) are on the hodder website for free so you get lots to work with. I need all the help and practice I can get......
#45 Re: Help Me ! » question to check - decimals dot notation » 2011-07-05 03:04:31
Hi silverpuma;
That is what I would do also. You are correct the 5 does not repeat.
Thanks Bobbym
#46 Help Me ! » question to check - decimals dot notation » 2011-07-05 02:47:08
- silverpuma
- Replies: 6
Hi my friends,
I need a second oppinion. My books asks me.............Write the recurring decimal 0.57373737373... using dot notation.
I gave the answer. 0.573 with the dots over the 7 and 3
The book gave. 0.573 with the dots over the 5 and 3
but the "5" does not recurr? It must be my age again....LOL
Thanks again
#47 Re: Help Me ! » another question to check please » 2011-06-30 21:42:58
correct.yes actually that is what it is called.
Thanks anonimnystefy no major blips this time LOL
#48 Re: Help Me ! » another question to check please » 2011-06-30 14:30:10
hi silverpuma,
Sorry about the late reply. I've been without my broadband connection all day. Just 'borrowed' another wi fi. (legally of course!!)
Opinions differ about whether a cylinder is also a prism (limiting case of a polygon with infinite sides) and whether a cone is a pyramid.
I used the MIF definitions.
When you get to the formulas for the volume of these solids the cylinder and cone share the same type of formula as the prisms and pyramids respectively. But I'm jumping ahead many lessons I suspect.
Yes, all correct. Glad you feel you are getting the hang of it.
Want one last net?
See below.
Bob
Hi Bob, Image attached. Just wondering as this according to MIF is not a prism what would it be called..............A hexagonal Pyramid ? Thanks again for the nets help its been appreciated
#49 Re: Help Me ! » Another book question to check » 2011-06-28 20:37:36
hi silverpuma
the book is correct for once
i think that you didn't subtract 60-58 to get the money spent only on coffee.
3/15=(3*1)/(3*5)=1/5≠1/3
aaaah thanks anonimnystefy I see it now:) These are the ones I could kick myself for getting wrong as the next day after I see the right answer it looks so obvious. But at the time I was wrong no excuses accepted
#50 Re: Help Me ! » another question to check please » 2011-06-28 20:29:07
hi silverpuma,
Yes, all correct! Well done!
Supplementary question on these solids:
Definition of a Prism:
A solid object that has two identical ends and all flat sides.
The cross section is the same all along its length.
Definition of a Pyramid:
The base is a polygon (a straight-sided flat shape)
The sides are triangles which meet at the top (the apex).
So for each of the solids in the question, (i) say what it's name is and (ii) say if it's a prism, a pyramid, or neither.
Bob
Bob, Iassume you are talking about the 4 shapes in the images you posted above?
A = Cube / Prism
B = Cylinder / Not a Prism
C = Square based Pyramid / Not a Prism
D = Triangular Prism / Prism
This has been really helpful Bob and I think I have a resonable grasp for now. I took your advice and cut out some paper nets or cubes, rectangles and pryrimds etc and this made things very clear for me. Now its decimals for lunch LOL