Lower Secondary Mathematics

PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.
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TeaBoh
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Re: Lower Secondary Mathematics

Post by TeaBoh » Mon May 09, 2016 3:35 pm

Hi

Can someone help on this question? (Without using calculator, show the workings)

Image

blissful mummy
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Re: Lower Secondary Mathematics

Post by blissful mummy » Tue May 24, 2016 8:12 pm

Is there a Math expert who can explain why the solution of the question:
In 2006, the price of one litre of petrol was $2.30. If the price of petrol in 2006 was 15% less than the price in 2005, calculate the price of one litre of petrol in 2005:
Is as follows:
Price of 1 litre of petrol in 2005 = 100/85 X 2.3 = $2.71

My question is: why is it 100/85 ( as in 100 divided by 85)?

Thanks so much!!! Really appreciate clarification on this :)

PiggyLalala
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Re: Lower Secondary Mathematics

Post by PiggyLalala » Tue May 24, 2016 8:22 pm

blissful mummy wrote:Is there a Math expert who can explain why the solution of the question:
In 2006, the price of one litre of petrol was $2.30. If the price of petrol in 2006 was 15% less than the price in 2005, calculate the price of one litre of petrol in 2005:
Is as follows:
Price of 1 litre of petrol in 2005 = 100/85 X 2.3 = $2.71

My question is: why is it 100/85 ( as in 100 divided by 85)?

Thanks so much!!! Really appreciate clarification on this :)
For questions on percentage, one has to be very clear of which quantity is equivalent to 100%, usually it is the original quantity or the quantity that we are comparing with will be 100%.
In this question,we are comparing the price of one litre of petrol in 2006 to the price in 2005. Hence 2005 price is equivalent to 100% and 2006 being 15% lesser, will be 85%.
Thus,2006: 85% - $2.30
2005:100%-$2.30/85x100=$2.71

blissful mummy
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Re: Lower Secondary Mathematics

Post by blissful mummy » Tue May 24, 2016 8:49 pm

Hi Piggylalala, really appreciate your clear and concise explanation, I get it now! Thanks v much for your kind help, really appreciate your time :) Have a lovely week ahead!

PiggyLalala
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Re: Lower Secondary Mathematics

Post by PiggyLalala » Wed May 25, 2016 7:24 am

blissful mummy wrote:Hi Piggylalala, really appreciate your clear and concise explanation, I get it now! Thanks v much for your kind help, really appreciate your time :) Have a lovely week ahead!
Glad that I could help. U have a nice week ahead too. :)


MyPillow
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Re: Lower Secondary Mathematics

Post by MyPillow » Sat May 28, 2016 8:57 pm

Sec 1 math has quite a fair bit of algebra , which I prefer.
Ds told me his class mate use psle model method to solve the story sum
Teacher gave that boy Zero ! Recall back, pri kids spends so many yrs
On hateful model , ended up not allowed in sec sch - Wat happen to math syllabus ? Pri n sec no linkages , why make the pri kids " suffer " so much nei :scratchhead:

cftan
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Re: Lower Secondary Mathematics

Post by cftan » Thu Jun 16, 2016 4:45 pm

Need help on this question.

The price of a sofa is $x. A man buys the sofa on hire purchase according to the following terms: a downpayment of 25% and the remaining to be paid in monthly installments over 30 months at a simple interest rate of 12% per annum. Given that his monthly instalment is $52, find the value of x.

Future Academy
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Re: Lower Secondary Mathematics

Post by Future Academy » Wed Jun 22, 2016 1:32 pm

cftan wrote:Need help on this question.

The price of a sofa is $x. A man buys the sofa on hire purchase according to the following terms: a downpayment of 25% and the remaining to be paid in monthly installments over 30 months at a simple interest rate of 12% per annum. Given that his monthly instalment is $52, find the value of x.
Image

Please let us know if you need further explanation, our team of ex IP school/RGS/NYGH teachers are here to support you.

Future Academy
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Re: Lower Secondary Mathematics

Post by Future Academy » Wed Jun 22, 2016 1:40 pm

MyPillow wrote:Sec 1 math has quite a fair bit of algebra , which I prefer.
Ds told me his class mate use psle model method to solve the story sum
Teacher gave that boy Zero ! Recall back, pri kids spends so many yrs
On hateful model , ended up not allowed in sec sch - Wat happen to math syllabus ? Pri n sec no linkages , why make the pri kids " suffer " so much nei :scratchhead:
Hi Mypillow,

There is a link between model and algebra actually. To certain extent, model is indeed a simplified pictorial presentation of algebra.

Primary school students cannot understand algebra well as it is quite abstract. So we use model approach to help students in understanding and visualising the questions.
However, model approach has its limitation as it is a simplified substitution of algebra. Therefore, teachers in secondary school insist that the students need to learn the more advanced and proper algebra, rather than always stick to model.

Cheers!

passioninlearning
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Re: Lower Secondary Mathematics

Post by passioninlearning » Wed Jun 29, 2016 9:49 am

MyPillow wrote:Sec 1 math has quite a fair bit of algebra , which I prefer.
Ds told me his class mate use psle model method to solve the story sum
Teacher gave that boy Zero ! Recall back, pri kids spends so many yrs
On hateful model , ended up not allowed in sec sch - Wat happen to math syllabus ? Pri n sec no linkages , why make the pri kids " suffer " so much nei :scratchhead:

This is the very reason why I always encourage students to pick up algebra at Primary 5 if they are competent, or Primary 6, to mitigate the loss of marks due to inability to draw models.


Regards,
Eric
passioninlearning.wordpress.com

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