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Mrs Tibble’s Year 8554 comments to Mrs Tibble’s Year 8 |
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Hi Mrs Tibble, by yellow book, do you mean the Level Up book, not the Zebra one?
Hi Mrs Tibble,
By yellow book, do you mean the Level Up book, not the Zebra one?
Sorry, I didn’t mean to send that twice.
Yes Gemma.
Thanks
Hi Mrs Tibble,
I know it’s really late, but I really don’t get question 5 on page 100. Could you please leave a message so that I can see it in the morning, as I will wake up earlier to have another go at it and complete some other homework.
Thanks,
Gemma
Hi Gemma,
Mode means most so modal group is group with the most in it ie the one with the highest frequency.
Is this a good average? Does it give a good impression of what all the data tells you?
Hope that helps. If not, don’t worry as we’ll talk about it in class.
JT
Hi. I was just wondering, what were the methods to work out a subtraction fraction. I’m stuck on 5 2/3 – 2 3/4. Can you help me please?
Hi Gemma,
That’s the one I went through in the lesson!
Make them top heavy, get a common denominator, then subtract and put back to mixed number.
OR
Change fractions only to same denominator, then subtract.
JT
I know it was the same one, I just forgot! I think I forgot how you did it, then when you went through it I remembered, then I forgot. Thanks
Is this right=
5 2/3 – 2 3/4 =
2 11/12
???
Gemma, write it down in case you forget again!!
Yes, that’s right.
You don’t need to ask me if it’s right – put it into your calculator and check it that way!
Oooooh, yeah! See, I wasn’t using my calculator at all. So much so, that I forgot I had one!
Thanks anyway
Hello, Mrs Tibble.
I don’t understand what I need to do for the homework problem…
I have miltiplied the 110 tonnes (per year) by 50 (years) but I don’t know what I need to do next.
Do I need to work out how much platinum has ever been produced EVER!? Then whether it fits into a shoe box etc.
Or do I need to work with the amount produced over the last 50 years and work out whether it would fit into a shoe box/ cupboard etc.?
Hi Jadzia,
If you look again, you’ll see that it’s the 50 years you need to work with because they say that before that the amount was negligible.
Remember to think carefully about the units because you have tonnes at the moment, but the density tells you how many grams 1cm-cubed is.
Have fun
JT
Thank you. I think I understand now…
Hey Mrs Tibble
I was wondering how I can access the answers to the test questions we got? Thankyou
Hi Zile,
Through the portal.
They are in Pupilshare, Senior School, Maths, Year 8, Year8 mark scheme JT
Have fun
JT
Hey Mrs Tibble,
I’m really confused about straight line graphs and how to get lines parallel to the axis. I get all of the y=mx+c stuff, it’s just the parallel lines that confuse me. I think we went through it in class but now I’m even more confused then before. Please help!
Hi Mrs Tibble, i have 2 things to ask, 1. what is the BEARING? and 2. im not sure what is meant by significant figures??????? Please help!
Hi Grace,
Draw yourself a graph – rough is fine – and draw a vertical line on it. Now choose points on that line and put their coordinates next to them. You should see a very obvious pattern straight away, and that is the rule for the line ie its equation.
Example: let’s say your vertical line goes through +4 on the x axis, then all your points will have coordinates (4, something). It doesn’t matter what the something is, the x value is always 4 and doesn’t depend on the y value. The rule is x is always 4 so the equation for this line is x=4. There’s no y in this equation because different y values all have the same x value.
The equation of a line only has both x and y in it when it slopes, because the 2 values depend on each other whereas for horizontal and vertical lines they don’t.
A horizontal line would be y=something because it is always that value whatever x is.
Hope that helps.
JT
Hi Lili,
Bearings are angles used for giving directions. They are measured CLOCKWISE from NORTH.
To work them out, face North at the place where your journey starts, then turn clockwise until you face where you want to go to. The angle turned through is the bearing, and it is always written with 3 figures.
Significant figures are the numbers which carry the information ie ignoring place value noughts.
Example 9876543 is a 7 digit number. The first non-zero number is the 9 so that is called the 1st significant figure. If we round this to 3 sig fig for example then we want to keep the 987. However, since the next number is a 6, this will round the 7 up to 8. So the numbers we keep are 988. BUT, they need to stay in the correct columns so that they still mean the same thing so we need to put zero into the other columns. Answer is therefore 9880000 to 3sf. only put zeros in if they are needed to keep the numbers in the right columns. eg 0.764532 rounded to 3sf is 0.76. You need the first zero to keep it decimal, but you don’t add zeros at the end because the numbers are already in the right place.
Hope that helps,
Mrs T
Hi miss Tibble.
Can you explain what standard form is please, I was answering some questions in the cgp book and i got to standard form and i dont get it ?!!?
hi mrs tibble i was confused about what standard for was using direct proportion
SORRY I MENT WHAT USING DIRECT PROPORTION MEANT AND WHAT USING STANDARD FORM MEANT
Hi Jessica,
Direct proportion just means when things change by the same factor eg if you buy 6 bottles of pop the price is 6 times that of 1 bottle. It’s a scary title for something fairly obvious!
Standard form is when numbers are written with powers of 10 eg writing 2 x 10-squared instead of 200.
See you tomorrow,
Mrs T
Hi Sian,
Sorry for the delay – didn’t see you had left a message.
Standard form is when you take the tens/hundreds/thousands etc out of a number and then write those powers of 10 using indices
eg 350 is the same as 3.5 x 100
so when it is written in standard form it becomes 3.5 x 10squared (sorry can’t do powers on here!)
See you tomorrow, and good luck,
Mrs T
Hi Mrs Tibble
I don’t understand exactly what we have to do for the homework on estimates etc. I know we have to write a paragraph but what on?
Hi Alberta,
Is this the heart-beat one?
Write a short paragraph explaining what we did to get the results on the sheet.
Then discuss the results in terms of what sensible accuracy for the answer would be – and why. Try to include all the reasons we came up with for why “exact” and “accurate” are meaningless in this context.
Does that help?
Mrs T
yeah thanks
Do we have to write up the newspaper/headlines thing aswell.
Hi Isadora,
Not write up exactly, but for the one you chose make sure all the thoughts your group came up with about the article are written onto it. Use paper if there’s not enough room.
Things like where has the number come from, is it believable, what is the headline about – what’s the message behind it – is the story deliberately biased or misleading, where have the figures come from…….
and anything else you discussed amongst yourselves.
Is that OK as a guide?
Mrs T
Yes thank you
Hi Mrs.T,
I had the same question as Isadora, and I read your reply to her, which was helpful, but on my table, my group didn’t really focus on one specific newspaper clipping. We kind of jumped from paper to paper, and we didn’t really discuss each clipping in depth, so I’m a bit confused on what to write.
Gemma
Hi Gemma,
Just choose one to work on yourself then using the points I left Isadora.
Mrs T
Thanks
Mrs Tibble, I am still stuck on the rapeseed oil thing.
I worked out that Rudolf’s idea works!
How?
Here
Here are my workings:
Assuming that 1/4 of cars are diesel than there are 6,552,000 diesel cars. (26,208,000 divied by 4)
39m/g
10,000 m/year
10,00 divided by 39= 266.5 gallons of diesel a year for one car
gallons per year x no. cars = 16,805,588,000 gallons for UK each year
Assuming that his figure is not including the biofuel mix, then to provide biofuel for 1/5 of diesel (336,117,600 gallons) we would need 84,029,400 gallons of biofuel.
4/5:1/5 = diesel:biofuel 4/5 divided by 4=1/5 ….
336,117,600=diesel=4/5 ….
336,117,600 divided bt 4 = 84,029,400)
3 tonnes of rapeseed oil/ hectare.
1200 litres biofuel / tonne rapeseed oil
650,00 hectares set aside land
3 tonnes x 650,000 hectares=no. tonnes of rapeseed oil for set aside land = 1,950,000 tonnes
1200 litres x 1,950,000 tonnes=2,340,000,000 litres of biofuel for set aside land
1 gallon = 4.55 litres
2,340,000,000 litres divided by 4.55 = 514,285,714.3 gallons for set aside land.
84,029,400 gallons of biofuel needed
514,285,714.3 gallons of biofuel produced by set aside land
Hi Jadzia,
There is a simpler way using the figure you used initially in class:
Use the total diesel figure near the bottom of the page – 19.44 million tonnes I think it was – and say 1/5 of that would need to be from the rapeseed oil ie approx 4 million tonnes.
You’ve said above that using the set aside land you could get just under 2 million tonnes so…………………….
Thank you…..
hmmmm…..
Wait! I have it! I get it now! Eureka! Thank you
Excellent! You can enjoy the rest of your weekend now
You’ve got that ‘won’t-let-go-till-I’ve-solved-it’ sort of mind which makes a good mathematician Jadzia! Hope you want to do A level.
Mrs T
Hi Mrs Tibble i have done my homework and it was not that hard!! See you on Monday!!
From Rachel
mañana!
Helloooooooooooo Mrssssssss Tibbleeeeeeeeee!!
Hello mrs Tibble!
just logging in
hello mrs tibble
Hi Mrs Tibble
just signing in!
Well done Rachel – nice when that happens
lol Eden!