tinker_bell\" post_id=\"2042110\" time=\"1634111500\" user_id=\"194652:

Compilation of TOP Math tuition centre solutions for the PSLE 2019 Semi Circles question

https://www.mycarforum.com/uploads/monthly_2019_09/71110475_2935986559762022_6972660636601810944_o.thumb.png.8e13b006b7b5cea2fbb3b01110982168.png\">

Visible math
https://www.facebook.com/visiblemathacademy/posts/2435331003187404

Nicklebee math
https://www.facebook.com/nicklebee.tutors/posts/2935987673095244
https://www.facebook.com/capital958/videos/2378118345785888

Compass Alpha math
https://www.facebook.com/permalink.php?story_fbid=1435822419902914&id=1029518567199970

Math heuristics
https://www.facebook.com/mathsheuristics/videos/1569789396496524/
https://www.facebook.com/mathsheuristics/posts/10162202186745004

Nice compilations, the variety of solutions here reminds me of those old Hwa Chong math olympiad solution book where they offer multiple solutions for some questions.
For me, I use the same method as Math Heuristics, since my MO brain is wired to look out for \"simple\" insights that could lead to solving the problem.
Koped from the video
https://postimg.cc/f3P7GvxJ

Garfield2882\" post_id=\"2128747\" time=\"1707437360\" user_id=\"188233:

What about other cca like coding?

AFAIK from being involved in dsa coding application process, can't speak for every school, the impression I get is that usually the schools offer coding/infocomm areas should have some teachers in charge, and set their own coding/computational selection tests and have their own additional criterias (e.g. interviews, portfolio evaluations) to evaluate the students.
Shouldn't be similar to sports situation at all, IMHO.

lucid\" post_id=\"2133049\" time=\"1713921373\" user_id=\"14312:

...
After arriving in the school, he found that humanes was as interesting and developed interest in literary works ( influenced from STEM classmates who read copiously). There is a resident poet teacher in the school too - go check the threads on the school. It is not all STEM as the children can pursue the humanes or music (Yong Siew Toh conservatory) to the highest levels at Uni level if they choose. Econs honours can be read at NUS for the 1XX-2xx series modules; they take the same tutorials and exams as the undergrads are marked agst their curve. Most do well as otherwise, they will not get back the extra fees charged by the uni. Motto of school is to Experiment, Explore and Excel. It applies to their entire culture and way of approaching life.

Out of Math, a number will embark on the Science/Informatics Olympiads with the free electives and reach National Golds and even national training team for International. Up until 1-2 yrs ago, R did not even offer CS as a core subject at As so it was doubly punishing to be pursuing CS and still having to clear your As with PCME combo.

MO at high level is not for everyone. By Y3-4, it would be clear who is cut out for it as very often, the students were taught WRONG as lower primary levels. The questions are meant for the alternate thinker who can find the most elegant solutions.
...

Nice sharing that even NUSH students could pursue interests and excel in humanities despite the school's original niche expertise on maths and science. I got the same takeaway when I watched their e-open house [youtube=https://www.youtube.com/watch?v=fFzs_zq0zuQ&list=PLvXZmd--7Vo4QP1lXQC733dncvAzwAt2r][/youtube].

By the way could you elaborate on why or how you think some of the students were taught wrong at lower primary levels?

gigilam\" post_id=\"2132962\" time=\"1713674546\" user_id=\"129870:

Hi…
As moe change new rule which no more streams as express , normal and NE…
I wonder does it mean DSA aim for normal neighbourhoods schools also useless?
Under old stream system… as long as you get in via DSA no matter to which school as least is under express…
Now under new system does it mean if not aim for popular school or IP … no point go using DSA for normal school as there will not be confirmation under express?

I get what you mean, certainly DSA for the popular/IP schools would be more popular since allows alternative route into the entry other than PSLE results that meets the school's COP.
But there's still merits for DSA to neighbourhood schools, for example if some family/child would like to pick a certain neighbourhood school or the child already had a strong interest in a cca, gaining that DSA usually allows benefits like accelerated route or higher chance to become part of the exco committee in upper secondary.
For example afaik ACS Barker robotics club sec1 DSAs get to train with the sec2s, on a different path from the other sec1 robotics.

Maple leaf:

dagong99:

[quote=\"berrymom\"

P5 already taking AMC 10 ? That's amazing ! :salute:

Berrymom, can Pm me your DS score for AMC8?Curious.

seems like the paper was hard as the famous P6 last year didn't get perfect score. He and a few others P6 last year were \"playing\" around the first row before the competition. DS was surprised to see someone who had got into SMO junior taking AMC8 :scared: .
Think somehow he was distracted . :nailbite: And did badly. Will let him try AMC8 again after his PSLE. He finds AMC8 manageable but AMC10 a beyond his level.

The P5s not eligible for AMC10.Wow,yr DS is P4 last year.Well done! :rahrah:

Just to share, AMC 10 is meant for Grade 9-10 students in US, but is typically taken by sec1-2 students in Singapore. Similarly, AMC 12 is meant for Grade 11-12 students in US, but is typically taken by sec3-4 and jc1-2 students in Singapore. Syllabus wise, there should be some questions topics in AMC10 that is beyond the P6 syllabus and which includes some sec1-2 maths.

berrymom:

dagong99:

[quote=\"Maple leaf\"]Oh,not till Feb? Okay, Thanks,Berrynom for the update.


Will ask DS l late about the AMC 10.

AMC 10A - 2 Feb
AMC 10B - 17 Feb

Thank you Maple leaf n dagong99 ! Does anyone knows what is e difference btw A n B? Or b more difficult ?
Ds jus told to go for 10b n I dun know if got time to practise w sch work now slowing piling up ...he tired I also tired...[/quote]http://www.maa.org/math-competitions/faqs/faqs-amc-1012
\" Both the AMC 10 A and the AMC 10 B have the same number of questions, the same scoring and the same rules for adminstration. The only difference is that each has a distinct set of questions, although the two contests are designed to be equal in difficulty and distribution of topics.\"

PlayfulFairy:

The key to a code is given by 3 whole numbers. The key is transmitted from the HQ by 3 agents, who were given the product of two of the 3 numbers. Suppose that the 3 numbers transmitted are 432, 540 and 720. What's the key code?


How do I solve the code? Thanks!

The key to solving this is to let the 3 numbers be represented by a, b and c where a < b < c.

Then there will be 3 possible products, a X b, a X c, b X c.
Note that a*b < a*c < b*c implying
a X b = 432
a X c = 540
b X c = 720

a X b X a X c X b X c = 432 X 540 X 720
a^2 X b^2 X c^2 = 432 X 540 X 720 = 167961600
Taking the square root of both sides of the above equation,
a X b X c = 12960
c = (a X b X c) / (a X b ) = 12960 / 432 = 30
a = (a X c) / c = 540 / 30 = 18
b = (b X c) / c = 720 / 30 = 24

Notice that this question ( & solution) is similar to the more common variant when you replaced the product by addition.

FantasyLandDreams:

Hi

Any MO trainer that teaches in the East? Could you pm me your location and charges please? Still cannot find any MO trainer or MO training center located in the East....

By the way have you tried/heard of MathArena or ExceLearn? MathArena is situated in tampines while Excelearn is situated in Parkway Centre.

Always21:

http://i62.tinypic.com/2pshhkm.jpg\"> Maths Guru,


Please help with this question. Unable to solve ourselves.

Thanks in advance

Hi Always21, may I ask what is the source of this question?
This seems to be a question beyond the average p6 students.

Key Idea #1:
Geometrically speaking, DP = PC means that triangle DPC is isosceles triangle, which also means that the point P is halfway between the two sides AD and BC. This is important because this means the point P lies on a symmetry line of the square ABCD.

Key Idea #2:
Let's ignore point Q for the moment and connect P to A.
Using the fact from key Idea #1, by symmetry, triangle APD is the same as triangle BCP! Hence the area of APD is 24 too.

Key Idea #3:
If u draw a line through P, parallel to CD (and AB),
and draw a line through P, parallel to AD (and BC),
you can kinda visualize that the total area of APD + BCP
is half the area of the rectangle ABCD, which means you now know that the area of triangle APB + PCD is 48.
Since PCD = 10, APB = 38.

From here on there are two methods ways to proceed depending on the background of the student.
The Smart Guess-And-Check method:
(Disclaimer: this method only works well if the sides are whole numbers)
Area of rectangle is AD times CD = 96.
Since the ratio of AQ : AD is 1:3, AD is 4 units and we can guess that AD is a multiple of 4.
Also given the area of PCD is 10, can guess that CD is a factor of 20.
By some guess and check can get that CD is 4 and AD is 24.
Then AQ is 6 and QD is 6X3 = 18.
From there on you can find the area of AQP is 1/2 X 6 X 2 = 6
Area of quadrilateral AQPB
= area of AQP + area of APB
= 6 + 38
= 44.

There is a method #2 which is more general and works even when the sides are not whole numbers. It involves comparing ratio of areas and is something that I teach my students for primary school maths olympiad.

meowchan:

Hi coffee cat,


I have absolutely no idea where the question comes from. Its a question by my P3 kid math teacher.

whatt!! in that I case I hope you reallie typo.. such that u actually meant 20¢ when u typed $20.
Unless your teacher was trying to act like Gauss's teacher, purposely gave a tedious question ... or to test how deep the parents' pockets is..
Did your teacher give as a homework question or challenge question or ?