Q&A - P3 Math

[tianzhu]

24hr-mum:

re the aziz question, why take the shortage and excess add together and divide by the difference in the number of pens? would be difficult to explain to my girl why do so. even i myself not so sure why.

Hi 24hr-mum

You need to apply a bit of logical reasoning here.

Let take a real life example of going to the hawker centre to buy the famous Teochew paos.

Assuming 1 pao costs $1 and you have $10.

If you buy 7 paos, you’ll have to pay $7, leaving you with an extra of $3.

If you want to buy 12 paos,you need to have $12.This means you are short of $2.

The difference between the number of paos( 12 and 7 ) is 5.

The gap between extra and shortage is $5.

In the Aziz’s question, the exact amount of money he has is unknown.
That’s why we draw a bar to represent his original amount of money which helps one to see the comparison between the two cases (6 and 8 pens)

Hope this helps.

Best wishes

[tianzhu]

24hr-mum:

does the sch actually give this kind of question in exam?

Hi

I am a parent; I can only share with you my experience in helping my kid in Maths during the last quarter of P5 and the PSLE year.

We relied mainly on worksheets given by the school and past years test papers from top schools (free from some websites).

Yes, such questions on “Excess and shortage’ are common in the exams.

Best wishes

[24hr-mum]

tianzhu:

24hr-mum:

re the aziz question, why take the shortage and excess add together and divide by the difference in the number of pens? would be difficult to explain to my girl why do so. even i myself not so sure why.

Hi 24hr-mum

You need to apply a bit of logical reasoning here.

Let take a real life example of going to the hawker centre to buy the famous Teochew paos.

Assuming 1 pao costs $1 and you have $10.

If you buy 7 paos, you’ll have to pay $7, leaving you with an extra of $3.

If you want to buy 12 paos,you need to have $12.This means you are short of $2.

The difference between the number of paos( 12 and 7 ) is 5.

The gap between extra and shortage is $5.

In the Aziz’s question, the exact amount of money he has is unknown.
That’s why we draw a bar to represent his original amount of money which helps one to see the comparison between the two cases (6 and 8 pens)

Hope this helps.

Best wishes

how to present the answer? is it draw models?
does the sch teach or we must somehow source the answers?

[tianzhu]

24hr-mum:

how to present the answer? is it draw models?
does the sch teach or we must somehow source the answers?

Hi

I’d say a MD helps students to arrive at the answers; it helps one to \"see\" Maths.

If you get more familiar with “Excess and shortage “types of questions, you may do away with drawing models.

I believe all questions in school exams should be covered in syllabus.

Best wishes

[rrjan]

Could anyone help me on this question please? How to show answer with model for this qsn?


Linda & Roy have a total of 255 stamps. Half or Linda’s stamps is twice as many as Roy’s stamps. How many stamps does Roy have?

Sincere Thanks,
Jan

[ksme]

rrjan:

Could anyone help me on this question please? How to show answer with model for this qsn?


Linda & Roy have a total of 255 stamps. Half or Linda's stamps is twice as many as Roy's stamps. How many stamps does Roy have?

Sincere Thanks,
Jan

I can't draw model. However, this is how I would work out the answer:

Half of Linda's stamps is twice as many as Roy's stamps
=> all of Linda's stamps would be 4 times as many as Roy's stamps

Total 5 parts (Linda's 4 parts + Roy's 1 part) => 255 stamps.
1 part = 51 stamps.

Therefore, Roy has 51 stamps.

[rrjan]

Thanks for your kind help KSMe, i think my boy will be able to understand your explaination as its very clear :celebrate:

[concernParent777]

Hi all,


I am stucked in a P4 Math question while helping out my son, any idea where I can post it? Thanks

[autumnbronze]

Hi,


:rahrah: :welcome: :welcome: :rahrah:

You may direct yourself to this link:

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=149&start=650

[concernParent777]

Thanks, but I have taken a picture of the question, how do I upload the pic?