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Mr Williams’ Year 8107 comments to Mr Williams’ Year 8 |
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Thank you.
I missed most of a maths lesson and not sure how to find the area of a circle using its diameter or radius. Any advice? Thanks
Hi Verity,
Area of a circle = pi x radius-squared
ie pi x radius x radius
If you only have the diameter you need to halve it first to get the radius before you start calculating the area.
Hope that helps.
JT
ah, i get it now!
Thankyou!
Well done Verity; glad you’re sorted!!
really stuck on the maths homework for the Q about a disc has a diameter of 12cm and a thickness of 0.8mm. What is the volume of a stack of 28 discs???????????? please help me
Hi Lauren,
A disc is like a very thin cylinder and I expect you have a formula for the volume of a cylinder in your book.
So you need to work out the volume of one disc (but be very careful as there are 2 traps in the data you have been given!!)
Once you’ve got that, multiply your answer by 28
do i need to do cross section?
Hi Lauren,
The cross section is the big circle of the disc, and the height of the cylinder is the thickness of the disc.
Hope that helps.
JT
on the h/w -pg 40 q 7
what does it mean find the value such that ?!?
please help !!!!
Hi Lauren,
It means that you need to work out the values of a and b which make the identity true. So if you multiply out the brackets on the left hand side and tidy it all up, the number of x’s on the left must be the same as the number on the right. Same with the y’s. That will tell you what values a and b have.
Hope that helps!! If it’s still as clear as mud, come back and tell me. Try the first one and I’ll check your answer.
Mrs T
for the first one i got 6x+12y ??!
Hi Lauren,
That’s correct so if the left hand side and the right hand side are identical to each other (that’s what the 3 line equals sign means) then a must be 6 and b must be 12.
OK now?
JT
yes thank you
what does the scale factor mean- does it mean that you times each lenghth by what ever the number is???????????????
for the h/w -pg56, q6
do you leave a space before you enlarge it, ot do you draw them really close together????
Hi Lauren,
The scale factor tells you 2 things:
1) how many times bigger all the lengths are, and
2) how far from the centre of enlargement to draw it.
eg a scale factor of 2 means twice as big and twice as far from C.
Does that answer both your questions?
Mrs T
Hello,am doing some last minute revising and what do you do if you have a question that says:27 to the power of -1/3 ??????????
Thank you
Lauren
Hello, I am not sure what indices means.
Please could you explain what it is.
thanks
For year 8 is the test non- calculator or calculator????
For tomorrow!
Hi Lauren,
1st paper is always non-calculator.
Indices are powers.
Power of 1/2 means square root and power of 1/3 means cube root.
Negative powers mean reciprocal or 1 over
eg 4 to the power of -1/2 means 1 over the square root of 4
The square root of 4 is 2
so the answer is 1/2.
Hope that helps, and good luck for tomorrow.
Mrs T
Hello Mr Williams,
I know its late but I had difficulty gaining access this site. I was a bit confused on Q2c and Q5 on p68 section 11.5. I tried working it out with my dad and I looked on the internet for any help but I just didn’t understand the question. I was wondering if I could possibly see you tomorrow lunch time
Hi Monique,
Is this the pie chart question?
2c Find the vegetarian section of the pie chart. What fraction of the circle is it? Since she ate 6 vegetarian pies, 6 is the same fraction of the total number.
Q5 Use a protractor to see what angle the rugby section is. This represents 120 people so you will know how many people each degree represents. A full circle is 360 degrees so that will lead you to the total number. For 2nd part measure angle and work it out from that.
Mrs T
Thank you Mrs Tibble
Hey Mr Williams
Please can i speak to you about how you find the circumfrance for a circle.
Thnx Tiffany
Hi Tiffany,
Circumference = pi x diameter
or 2 x pi x radius
Area = radius-squared x pi
Hope that helps.
Mrs T
hi mr williams
i have found my maths watch cd and have put it into my computer now i can’t do my revision because i have forgottenhow to do it ! please help me asap as i need help!
thank you maddy
Hi Maddy,
If you put the disc in the computer then you should get a home page. If not then go to ‘my computer’ and start it from there.
Once at the homepage, try clicking on one of the links eg topic. You will get a list of maths topics ordered by grade and then alphabetically. Try clicking on one of them. You’ll get a presentation with voiceover and questions that follow.
Hope that helps.
mr williams
yes but what do i do after that it comes up with four files
only problem is that i have an imac! what dod i do or is it the same for them?
maddy
Hi Maddy,
I think you’ll find at the top of the disc it says you need Windows to run it, so it won’t work on your imac: you’ll need to use a windows PC.
Mrs Tibble
Massy, check your letter – it said that the discs will not work on apple computers. There is a bit of software that will allow it but you would need to check with a computer expert. I think it’s called an emulator
Sorry to spell your name like that maddy! – keyboard on my phone is hard to use
Hi
I am revising for my maths exam but I can’t remember how to find the range of a number from a stem and leaf graph
Hi Anujaa,
The range = highest value – lowest value
which for a stem and leaf diagram are the first and last values because the data is sorted.
Hope that helps.
Have a lovely Christmas.
Mrs T
thank you Mrs Tibble
I DON’T UNDERSTAND HOW TO DO QUADRATIC EQUATIONS . MERRY CHRISTMAS AND HAPPY NEW YEAR
Hi Anujaa,
If you are in year 8 you don’t need to!!
Save that treat for next year
Mrs T
thank you mr willaims and ms tibble that is fine i pluged it into my laptop which is windows and now its working. do you know what day the maths exam will be on?
maddy
Hi Maddy,
If you are year 8, it’s in your maths lesson on Monday 9th.
Mrs T
hi Mrs Tibble I don’t understand this QUESTION WHICH IS WRITE IN THE INDEX FORM B CUBED TIMES B SQUARED AND A TO THE POWER OF 5 TIMES A TO THE OF SEVEN
Hi Anujaa,
Index form means using powers. So b-cubed x b-squared means that altogether you would be multiplying five b’s; the answer is therefore b to the power of 5. (ie when you multiply, ADD the powers)
You should be able to do the other one yourself now.
If in doubt, think about what indices mean.
Mrs T
hi Mr Williams i am a bit stuck, do we have to learn timesing, multiplying and subtracting and adding fractions for the test?
madddy
hello again just wondering if this maths site had a mymaths acount if so could you please tell me the details?
maddy
Hi Maddy,
Everything with fractions is important – from year 7 to A level!!
No, we don’t have a mymaths account.
Mrs T
hi Mrs Tible
yes so i do need to revise that!
ok i was just wondering as i looked quite good, could you name any good revision sights?
Maddy
Hi Maddy,
Try mathsnet.net
Click on fractions in the pink box and see what you can find in there. They do some step-by-step worked examples.
Mrs T
Fractions will be in the exam – make sure you can do adding, subtracting, multiplication and division and ordering. See you on Thursday
hi I don’t understand how to divide fraction
Hi Anujaa,
You don’t! Turn the fraction you are dividing by upside down and multiply instead.
eg 5/8 divided by 3/4
becomes 5/8 x 4/3 = 20/24 = 5/6
Do both calculations on your calculator to convince yourself this works.
Mrs T