PSLE Maths question. How to solve? Options

[Windcloud03]

Algebra is taught in Primary school but NOT simultaneous equations, ie they only have one unknown.

You can use ALL methods to solve the questions, including algebra. MOE replied to a ST forum letter officially.

my solution using only algebra without simultaneous equation.

can they use algebra? thought not supposed to do so? where's MOE's reply?

[Josho]

I'll die when my kid taking PSLE next time.... Im poor at all subject especially Math. Now it is not just kids need to be good but parents as well.

Not easy...

[Milo]

bro, engage a tutor, a pro one.

[Jamstart]

I think more than 50% of the adults here cant solve this question.

[Josho]

bro, engage a tutor, a pro one.

Yeah lo.... i dare not to think 10 years down the road.. how tough the education will be.

[Milo]

Yeah lo.... i dare not to think 10 years down the road.. how tough the education will be.

dont worry, no matter how tough the education will be, as long as the kids have the right attitude, there will always be assistance n guidance.

[Leslielai]

Tadah

If its not clear enough I can further elaborate

*edit - sorry, got plotting errors in my first picture



This post has been edited by Leslielai: Oct 12 2009, 12:27 PM

[Tunge]

Tadah

If its not clear enough I can further elaborate

woohoo u r good

[Josho]

I still very blur on the working sum

Why must 12 x 4 + 18?
Sweet is 2 units?

Sorry ah.. I am very bad at math... just want to understand more...
Bloody lost.

Thanks for the good effort, Leslielai.

The amended graph made me even confused.

This post has been edited by Josho: Oct 12 2009, 12:30 PM

[Leslielai]

I still very blur on the working sum

Why must 12 x 4 + 18?
Sweet is 2 units?

Sorry ah.. I am very bad at math... just want to understand more...

Bro,

No problem. Here goes

1. We start out by plotting the diagram for Jim, with a unit to indicate the amt of sweets he has left + the dotted area indicating that he has consumed 12 sweets.

2. Next, since we know that the amount of chocolates he has left is 7 times the sweets he has left. Therefore, 7 units

3. Following that, we can now plot Ken's diagram. Bear in mind that he did not consume any sweet at all and that what he has should be what Jim had initially (inclusive of the dotted area representing the 12 he consumed). This time round we use a regular line to include 12, not dotted line as it still exists. In doing so, we can obviously tell that each unit of Ken's sweet or chocolates for that matter is equal to one unit of Jim's, PLUS 12.

4. Follow through by drawing 4 times of the above.

Recall that since the amt of chocolates Jim has (which remains unchanged) should be equal to the amount Ken had at the first. We'll extend the chocolate diagram for Ken to the same length as Jim's. This represents the 18 Ken has consumed.

Since in step 3, the units for Ken is drawn in such a way that every unit of his sweets/chocolate is EQUAL to each unit of Jim's PLUS 12. Therefore, the difference in terms of units between Jim and Ken should equate to all the numerical differences denoted by 12, 12, 12, 12 and 18.

The key here is in mapping Ken's model. Each unit in Ken's term is one unit of Jim's plus 12.

This post has been edited by Leslielai: Oct 12 2009, 12:46 PM

[Vroomtattat]

woohoo u r good

Give the man a tigerrrrhhhhhh . . . . .

[Kusje]

My son told me after he got out of the exam hall that some of his peer has got no time to finish some of the question.Some as many as 5 questions...

I just told him to move on and since you have done your best , don't look back and go play balls .

I think a lot of people have been brainwashed to believe that as long as you try hard enough, you will succeed. They end up spending 15 minutes on a stupid 5 mark question that they cannot solve and refuse to move on; these are the ones who end up coming out of the exam hall in tears because they can't finish the paper.

Same goes with life. Not everyone can become the POTUS, not everyone can be the next Bill Gates. Everyone should learn about their own capabilities and set reasonable goals instead of setting themselves up for failure.

tldr, some people watch too much Forrest Gump.

[Jamstart]

If you think this is blur, look at these sums. (got from another forum)


Shop A has 156kg of rice, while Shop B has 72kg of rice. Each shop sold an equal amount of rice and after that the ratio of the amount of rice left in their shop was 4:1. Find out how much rice has been sold. (3 marks)


6/14 of the chairs in the hall are in rows of 13. Half of the chairs in the hall are in rows of 7. There are 112 more chairs in rows of 7. The rest of the chairs are stacked up. Find out the total number of chairs in the hall (5 marks)

6 friends decided to rent computers from 2pm to 4.30pm. While 4 of them were playing, the other two would watch. If the cycle continues, and each of them played for equal number of minutes, how many minutes will each person get to play?


Mei and Lin were in a bicycle race. Mei was travelling at a constant speed of 20km/hr and they both did not change their speed. When Lin completed half the race, Mei was 3.5km ahead. Mei completed the race at 10.45am. What time did Lin complete the race?


Sally baked some cookies to sell. 3/4 of them were chocolate cookies and the remaining were almond cookies. After she sold 5/6 of chocolate cookies and 210 almond cookies, she had 1/5 of the cookies left. How many cookies did she sell?



Curry puff shop sells puffs at $0.80 each. Offer:Buy 3 get 4th half price. If customer has $50, how many puffs can he buy if he buys as many as he can.


String of 2 big balloons is 90cm
String of 5 small balloons is is 1.2m
If both strings are of the same length, there would be 105 more small balloons than the big balloons. How many balloons are there altogether?

This post has been edited by Jamstart: Oct 12 2009, 02:11 PM

[Joe25]

can they use algebra? thought not supposed to do so? where's MOE's reply?

now i'm going to worry for my kids liao

[Jman888]

I think a lot of people have been brainwashed to believe that as long as you try hard enough, you will succeed. They end up spending 15 minutes on a stupid 5 mark question that they cannot solve and refuse to move on; these are the ones who end up coming out of the exam hall in tears because they can't finish the paper.

Same goes with life. Not everyone can become the POTUS, not everyone can be the next Bill Gates. Everyone should learn about their own capabilities and set reasonable goals instead of setting themselves up for failure.

tldr, some people watch too much Forrest Gump.

some not thinking strategically, every mark counts to make it to the 状元榜! or be the 状元 of the year! that alone like going to make or break their future.... sad

[Contax]

those are the 2009 PSLE exam question ?

[Bavarian]

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. Are they GAY?

Ans: 69

[Jamstart]

I got it from another forum, i think so ba.

[Kusje]

If you think this is blur, look at these sums. (got from another forum)

Those questions are quite simple and comparable to the PSLE questions I took about 15 years ago. By the way, people should not complain that the questions are getting harder; they are supposed to be! Technology and science is advancing so fast these days that everyone (not just in Singapore) will need to cram more material into their brains. New theories and laws are coming out everyday, should a physics major complain that people 100 years ago didn't have to learn about e=mc^2 and that his course workload is increased?

[Nozzie]

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. Are they GAY?

Ans: 69

Just as I was getting all worried for my sons... WAHAHAHA!!!! Good one bro...