Standard Math Q+A Thread

[jakesilove]

Hi!
I was just wondering if anybody could let me know if in a General Mathematics HSC exam, they could ask us to draw a radar chart and fill in the information given for it?
I have just done a practice question from an Excel book, and they asked me to draw a radar chart, but I have never seen this in a past HSC paper before??
Thankyou!

Hey!

I didn't go General Maths, but taking a quick look through a bunch of past papers makes me think that this is the sort of thing that they will always give you, and leave for you to interpret, rather than ask you to draw yourself.

That being said, if it is in the curriculum, they definitely COULD ask you to draw something like that. It is even more likely in Trials, where questions are often quite different to HSCs, and in fact sometimes are quite a bit harder. I would be familiar with things like drawing Radar charts, just because they could ask you to, but I wouldn't worry much about it.

Hopefully someone with more General maths experience can jump in here and help me, but I think it's fair to say you should be ready to draw it, even if it is unlikely.

Jake

[Ragdolls]

Hi!
I was just wondering if anybody could let me know if in a General Mathematics HSC exam, they could ask us to draw a radar chart and fill in the information given for it?
I have just done a practice question from an Excel book, and they asked me to draw a radar chart, but I have never seen this in a past HSC paper before??
Thankyou!

Hey Emmaperry,

As far as I know, my maths teacher has told us to only worry about reading radar charts. I don't think we will have to draw one in the HSC exam, but just know the basics just in case. When I do past papers, the only trend I've seen is that we get radar charts and we need to know how to read and interpret them in order to answer the questions following.

[victoriad98]

Hey Jamon, so I really struggle in Math with conversions, like converting 1mm into 1km, or mm into L, and it really stuffs me up when I get a question where I have to do a large conversion because I just get so jumbled up! Do you know any good techniques/ways with conversions? thanks 

[Gregs]

Hi Victoria
In regards to converting mm to km you simply just divide the amount of mm by 1 million (km = mm ÷ 1,000,000)
e.g. the length of the road is 490 345 956mm long, how long is this in km?

490345956 ÷ 1 000 000= 490.345956km long

I haven't seen a question asking this but I have seen questions asking you to convert the length in kilometres into length in metres then into centimetres and finally into mm.

This may seem daunting at first due to the amount of numbers required to figure these values out but all you need to remember (write in your notes) is that:

in 1km there are 1000 metres (x1000)*
in 1 metre there are 100 centimetres (x100)*
in 1cm there are 10 millimetres (x10)*
*Change the multiplication symbol to a division symbol to work back the other way
If you can remember this (which is simply the best tip i can give) and you are faced with a question like, How many mm in 560km? You can easily figure out the answer through the process of first working out how many metres then centimetres and finally millimetres.

560km x 1000 = 560 000m
560 000m x 100 = 56 000 000cm
56 000 000cm x 10 = 560 000 000mm

In regards to converting mm into L it's not really possible. You'd have to work out the volume first then convert it to metres
I found a website that is great for converting these sorts of things that also provides a description of how they do these conversions:
https://www.checkyourmath.com/index.php

Hopefully this helps

[jakesilove]

Hey Jamon, so I really struggle in Math with conversions, like converting 1mm into 1km, or mm into L, and it really stuffs me up when I get a question where I have to do a large conversion because I just get so jumbled up! Do you know any good techniques/ways with conversions? thanks 

Hey!

Just a quick addition to that great answer; most of the time, you'll only need to convert from the standard unit (ie. Liters, Meters etc.) into kilo or milli versions of that unit (ie. kilograms, millimeters etc.). So, you just need to remember how they work!

For a unit (eg. m), the 'kilo' unit (eg. km) will be 1000x more that unit
For a unit (eg. m), the 'mili' unit (eg. mm) will be 1000x less that unit

If you need to convert from mili to kilo, you just multiply by 1000 to get to the normal unit, then 1000 again to get to the kilo unit! Spend some time playing around with these conversions; they're important to understand Thanks Gregs for the awesome response!

[jamonwindeyer]

Hey Jamon, so I really struggle in Math with conversions, like converting 1mm into 1km, or mm into L, and it really stuffs me up when I get a question where I have to do a large conversion because I just get so jumbled up! Do you know any good techniques/ways with conversions? thanks 

Hey Victoria! Greg and Jake have given awesome responses, and what I'll stress from it is that I hated conversion. A little pet peeve of mine  definitely you should do it in steps like Gregs did a bit further down, those involve conversions that are easier to remember! Alternatively, remember all of the prefixes like Jake suggested, which is my preferred method (being a Physicist, they teach that method there).

The other thing that messed me up a lot was conversions in 2 or 3 dimensions. For example, square centimetres to square metres. To do this, consider the formula for metres-centimetres:



To figure out the conversion of square metres to square centimetres, let's just \textbf{square both sides of this relationship}.



This is a really easy way to get the conversion rates yourself instead of remembering them! Just a neat little trick, hope it helps! 

[victoriad98]

Thanks guys this really helped 

[kmorritt]

Two simple suggestions:

Use a highlighter.
Copy out valuable pieces of information CLEARLY stating what it is on the SIDE.

thank you this is really good advice. I never used to highlight

[Gregs]

Hi,
I was just wondering how you answer this question,
Milla enters $58 a month into a superannuation fund. It is expected that the fund averages 12%p.a compounded monthly. Find the expected value of the fund after 25 years

I get all the divide 12% by 12 to get the rate of the monthly compound and multiplying 25 by 12 but what equation do you use to add the $58 each month into the end result.

Cheers, Gregs

[jamonwindeyer]

Hi,
I was just wondering how you answer this question,
Milla enters $58 a month into a superannuation fund. It is expected that the fund averages 12%p.a compounded monthly. Find the expected value of the fund after 25 years

I get all the divide 12% by 12 to get the rate of the monthly compound and multiplying 25 by 12 but what equation do you use to add the $58 each month into the end result.

Cheers, Gregs

Hey Gregs! So this is a future value of an annuity question, and there is a formula for this:



Where M is the contribution every period ($58 per month), r is the interest rate (12% divided by 12), and n is the number of periods (300 months).

Is this a formula you have learned? It's not on your Formula Sheet, but I think it's covered as part of the Financial Math part of the General Math course

[Gregs]

  Thanks Jamon, I can't remember seeing it in class but I'll try and remember it for the exam tomorrow ahah I was thinking it could've been one of those questions not in the syllabus any more.

[RuiAce]

  Thanks Jamon, I can't remember seeing it in class but I'll try and remember it for the exam tomorrow ahah I was thinking it could've been one of those questions not in the syllabus any more.

It probably is. I found it on the outdated formula sheet but not the current one.

As in it's probably one of those not in the new syllabus

[jamonwindeyer]

It probably is. I found it on the outdated formula sheet but not the current one.

As in it's probably one of those not in the new syllabus

Brilliant sleuthing Rui, thanks for that

  Thanks Jamon, I can't remember seeing it in class but I'll try and remember it for the exam tomorrow ahah I was thinking it could've been one of those questions not in the syllabus any more.

No need to worry about it in that case Gregs, definitely not assessable anymore, good luck for your Trial!! 

[stephanieazzopardi]

Hi,
I was just wondering how you answer this question,
Milla enters $58 a month into a superannuation fund. It is expected that the fund averages 12%p.a compounded monthly. Find the expected value of the fund after 25 years

I get all the divide 12% by 12 to get the rate of the monthly compound and multiplying 25 by 12 but what equation do you use to add the $58 each month into the end result.

Cheers, Gregs

Hey Gregs! Okay so in the exam you may get a question like this, but you will be provided with the contribution/annuity table! So all you need to do is line up the rate with the number of periods from the table according to the question, and times that compounding factor from the table by 58. As long as everything is in months you should get the answer!! Please note: You will always be provided with a table and WILL NOT need the annuity formula as mentioned by Jamon (bloody Extension kids trying to do General ) Good luck!! Please ask more questions if need be!

[jamonwindeyer]

Hey Gregs! Okay so in the exam you may get a question like this, but you will be provided with the contribution/annuity table! So all you need to do is line up the rate with the number of periods from the table according to the question, and times that compounding factor from the table by 58. As long as everything is in months you should get the answer!! Please note: You will always be provided with a table and WILL NOT need the annuity formula as mentioned by Jamon (bloody Extension kids trying to do General ) Good luck!! Please ask more questions if need be!

Rekt