2009 Maths Question which Adult also duno!

[cheeseme]

What's the big deal? The big ho-ha is just that now every parents want their kids to score 100/100. That's why every questions count. In the previous generation, who cares. So why the different now? Because every parents are paying so much on tuition fee, so they expect 100% results!!! Haha, perhaps that's the bottom line, and the norm behaviour for parents like us in Singapore.

BTW, IMHO for those parents who have shared their time teaching their kids, than leaving them to the "Professional" or tuition teachers. They will find no problem solving this question also and exactly how it should be done the P6 way. Simultaneous equation is not a preferred method for P6.

 

[gohaj]

This year PSLE!

From Yahoo Sg:

Jim bought some chocolates and gave half of it to Ken. Ken bought some sweets and gave half of it to Jim. Jim ate 12 sweets and Ken ate 18 chocolates. The ratio of Jim’s sweets to chocolates became 1:7 and the ratio of Ken’s sweets to chocolates became 1:4. How many sweets did Ken buy?"




Anyone? Me still trying!:sweat:

simple simultaneous equation.

assume jim buys c chocolates, ken buys s sweets.

at the end, jim will have c/2 chocolates, ken will have c/2 - 18 chocolates
at the end, jim will have s/2 -12 sweets, ken will have s/2 sweets

c/2 = 7(s/2 - 12) = 7s/2 - 84 --- (1)
c/2 - 18 = 4(s/2) = 2s --- (2)

from (2): c/2 = 2s + 18 --- (3)

sub (3) into (1)

2s + 18 = 7s/2 - 84
so 102 = 3/2 s

s = 68
c = 308

checked the answer is correct;

jim has 154 chocolates, ken has 154- 18 = 136 chocolates
ken will have 34 sweets, jim will have 22 sweets

154/22 = 7
136/34 = 4

QED

The question is a tough one even for me!:bsmilie:
The way you present it, I almost cannot find the answer in your working.:think: The question is "How many sweets did Ken buy?". Your answer is hiding in the working.:sweat:

With such question in test/exam, I am also worried that I cannot cope in guiding my kids.:sweat:

 

[LenzLaw]

The usage of algebra and simultaneous eqns would have made things a lot easier.

Always hated drawing models back in Pschool...;p

 

[cheeseme]

Dun believe? It's really that simple. Just draw the model. "S" = 1 part; left hand is Jim || right hand Ken. In RED = eaten

chocolates = S S S S S S S || S 12 S 12 S 12 S 12 18
sweet = S 12 || S 12

Cancel away all the "S" and "12", what's left is

chocolates = S S S || 12 12 12 12 18
so, "S S S" = 12 + 12 + 12 + 12 + 18 = 66. Therefore "S" = 66 / 3 = 22.

Hence, Ken bought S + S + 12 + 12 = 22 + 22 + 12 + 12 = 68 sweets.

Difficult? Hello, this is exactly what our MOE guided and paying their teachers to teach our Primary school children. BTW, my P5 daughter answered it in minutes by this method, and the above answer was what she gave me.

The what Sakamoto Method given in one of the link is more confusing to the Kids, and the simultaneous equation way is worse, isn't it?

Haha, but unfortunately everyone now a day think : amount of money out = amount of result in. Sadly, the fact is a good method for an adult may not be good for the Kids. But how many parents now a day actually got time and effort to discuss with their kids and try to understand this?

For some perhaps, spending money on their kids is also a way to settle their guilt for having to put most of their time in making money for a better living for themselves, than really knowing what their kids actually want.

Nevertheless, this are the RAW facts that I'm witnessing every day in Singapore.

How parents, any comment? Especially for those who think this is a very very touch question. This is what I get in return after spending time learning the methods she is being taught in school and coaching her based on what she suppose to know. MOE really didn't try to make thing hard for the kids. Perhaps are the parents giving too much to the kids which is really not necessary.

 

[night86mare]

The question is a tough one even for me!:bsmilie:
The way you present it, I almost cannot find the answer in your working.:think: The question is "How many sweets did Ken buy?". Your answer is hiding in the working.:sweat:

With such question in test/exam, I am also worried that I cannot cope in guiding my kids.:sweat:

it's there mar..

i also not taking exam. the ones taking the exam need to write.. ken bought 68 sweets lor.

 

[night86mare]

Difficult? Hello, this is exactly what our MOE guided and paying their teachers to teach our Primary school children. BTW, my P5 daughter answered it in minutes by this method, and the above answer was what she gave me.

yes, model drawing is after all, a substitute for algebra, you use blocks instead of x, y, c, s, whatever!

anyways.. well, not everyone has equal interest in studies. be glad that your p5 daughter can answer it.

 

[FLiNcHY]

I think the real question here is Why are two boys buying sweets for each other?
:think::think:

 

[night86mare]

P.S- I find it kinda dumb that algebra isn't allowed in the PSLE though :sticktong

me too.. i always had to reverse engineer model drawing, i remember.

 

[cheeseme]

yes, model drawing is after all, a substitute for algebra, you use blocks instead of x, y, c, s, whatever!

anyways.. well, not everyone has equal interest in studies. be glad that your p5 daughter can answer it.

Agreed, not everyone has equal interest. That include my daughter. We always quarrel every time I opened her book. And she will give me that face ;( the moment I talk. It require a lot of effort and patience to sync with her. But how can we parents give up? Else, we should not be having them in the first place.

 

[ggodetucsamoht]

to me is like the educational system is getting higher and higher in standard. sometimes it is not just a matter whether our parents is giving proper coaching to the kids but it is just a standard that is far beyond our knowledge to give them proper guiding that something we dont even understand.

imagine, the future who know the school will teaches our kid to make automic bomb???

 

[aryanto]

The problem is the parents did not study the model method, while struggling with kids who are asked to do this.

I also solve this with algebra, and really algebra (and its higher cousins like calculus, integration, fourier series etc) is the one that work in real world working life esp those working not in whole numbers.

 

[melvin]

cheeseme:thumbsup: for ur P5 daughter who can solved it!

Agreed with some that the smarter kids will avoid this question n concentrate on the rest! For me i will do the same also!

IMO:
I think nowadays its the parents whose expectation is way too high for the kids which resulting the kids strees out! When they can't do the question they will cry cos afraid they cant get good results or get 100%.

Once heard that a P5 boy jumped down from HDB flats all because he didnt did well enough or up to his parents expectation.

Another case is also pri school kid other then his school lesson the kid got another 11tuition and other classes or courses to attend in the end child threaten to commit suicide parents then cut down to 7.

Think these are really sad cases. Why parents' set too high of expectation for the poor kids, just imagine the amount of pressure the kid have to handle!:sweatsm: Think they will be better off in a 'pressure cooker' environment then under such expectation!

Some times we got to face it not every child is the same or perfect, so dun expect the kids to be the same as those who get 100% by comparing them is not ideal.

I know its every parents dream/wish that their kid turns out to be Dragon or Pheonix,望子成龍望女成鳳, but before this we need to know our children's capability / interest and their limitations where their strength n weakness are develop from there, not everything dump into them n also not everything know must learn.

In short develop a child within his/her capability!

 

[baggiolee]

sometimes it's not the pressure from parents...it's about the kid's own expectation and the fact that he does not want to let his parents down.

i used to fail my english in p4 and got into extended class (8 yrs instead of 6 yrs)...i keep the results as a secret for more than 1 week. luckily my tutor and my parents never pressure/demand me for my results, if not i jump liao.

 

[La Fontaine]

Well, it doesn't matter what you score in PSLE, or A level.

Just got to take note that it is which direction you go after that that counts.

A car salesman makes 8k a month.
A stock broker makes 12k a month
A property agent makes 20k a month.

Go figure that out.

Engineers, accountants, lawyers, doctors make much less than that. This is just a general statement. There are exception, of course.

 

[DeSwitch]

Here is how I show my kid how it is done at their level using what was taught by their teacher.

 

[lancey]

we found this solution for our son:
http://www.sakamoto.net/web.php?pg=6&type=article

check on the 8 oct 2009 link, u will find the answer there.

wtf.wtf

 

[kiwitan]

Here is how I show my kid how it is done at their level using what was taught by their teacher.

Your kid must be a genious!

 

[ArcticFox]

simple simultaneous equation.

assume jim buys c chocolates, ken buys s sweets.

at the end, jim will have c/2 chocolates, ken will have c/2 - 18 chocolates
at the end, jim will have s/2 -12 sweets, ken will have s/2 sweets

c/2 = 7(s/2 - 12) = 7s/2 - 84 --- (1)
c/2 - 18 = 4(s/2) = 2s --- (2)

from (2): c/2 = 2s + 18 --- (3)

sub (3) into (1)

2s + 18 = 7s/2 - 84
so 102 = 3/2 s

s = 68
c = 308

checked the answer is correct;

jim has 154 chocolates, ken has 154- 18 = 136 chocolates
ken will have 34 sweets, jim will have 22 sweets

154/22 = 7
136/34 = 4

QED

Sure that work but don't forget that simultaneous/equation are not thought in primary school.

Anyway, this question is at most and at least 5 marks so even though you had not done this you could still get a A* by perfecting the other question.

 

[night86mare]

Sure that work but don't forget that simultaneous/equation are not thought in primary school.

Anyway, this question is at most and at least 5 marks so even though you had not done this you could still get a A* by perfecting the other question.

can solve with model drawing i guess.

simultaneous equation basis is to put number of chocolates in terms of number of sweets, or vice versa.

you can easily do that with model..

 

[DeSwitch]

Your kid must be a genious!

No lah, They are not genius. They ask me what the question was as everyone was talking about it. They dunno how to do but I just showed them how its done using the method taught by their maths teacher. Took me some time to figure it out too. Using algebra would be easier. :sweat: