PSLE - New Format for Maths

[Guan Hui]

Hello this is what I get from the channelnewsasia forum. I am a tuition teacher who has students taking PSLE so I am quite concern too. Below are the questions and the suggested answers I provide.


PSLE Maths - some of the questions
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? Ans: 11.06am

Suggested Answer:
3.5 x 2 = 7km(how much ahead is mei if she keep cycling when Lin finish the race)

speed= 20km/h
7km= 7/20 X 1
=0.35 hr
=21 mins (time needed to be 7km ahead for mei)
Time when Lin complete the race = 10.45am+ 21mins
= 11.06am




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? Ans: 960

Suggested Answer:
5/6 of chocolate cookie = 5/6 x 3/4
= 5/8 of total cookie (SOLD)
Faction of cookie sold = 1- 1/5
=4/5
Fraction of Almond cookie Sold = 4/5 - 5/8
= 7/40(SOLD == 210 almonds)
4/5= 32/40

7units =210 almonds
32 units = 32/7 x 210
= 960 cookies

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?. Ans: 68 sweets

Suggested answer:

Jim Ken
sweet : Choco Sweet : Choco
1Junit : 7Junits 1Kunit: 4Kunits
1Junit+12 : 7Junits 1Kunit: 4Kunits +18 (before eating the sweets and the chocolates)

Since at the beginning they have the same number of sweets and chocolates.
1Junit + 12 = 1Kunit
4Junits +48 = 4Kunits
4Junits + 66 = 4Kunits +18 = 7Junits
3Junits= 66
1Junit= 22
Number of sweets Jim recieved at the beginning : 22 +12 =34 sweets
Number of sweets Ken buy : 34 +34 =68 sweets
(Regret cant show in model)

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. Ans: 71 puff

Suggested Answers:
3 puffs : $0.80 x 3 =$2.40
4th puff: $0.80 / 2 =$0.40
1 set of 4 puffs cost: $2.40+$0.40=$2.80
Number of sets the customer can buy with $50: 50/2.8=17 sets and $2.40 left
Number of puffs $2.40 can buy: $2.40/$0.80 = 3puffs
Number of puffs in 17 sets: 17x 4 = 68 puffs
Total number of puffs: 68 +3=71 puffs

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? Ans: 345

Suggested Answers:
String of 1 big balloon: 90cm/2 = 45cm
String of 1 small balloon: 120cm/5 = 24 cm
difference in the length of string: 45-24=21 cm
how much longer if they have the same number of big balloons and small balloons: 105(small balloons more) x 24= 2520 cm
The number of big balloons that will cause this difference: 2520/ 21 = 120
Number of big balloons: 120 balloons
Number of small balloons 120+105=225 balloons
Total: 120+225= 345 balloons

This is my 10cent worth of solution hope it helps to further confirm your children answers. Anymore enquires about maths you can call me at 94503822=) I will gladly assist you.
Good luck to all those children taking science and higher chinese next week=)

[kohjl]

StudentABC:

I think I die le. I went home and cried that day. In fact many ppl could not complete.

Hey StudentABC

Don't feel too bad....you didn't do particularly badly because many students also could not do many sums, so you are not alone. Don't be sad....you must pull yourself together and aim to do well in Science which is on Monday.

When my eldest son took his PSLE a few years ago, he was also sulking after the Maths paper as it was also very difficult that year, but he did very well in the end. So you never know cos MOE will moderate the results.

So...focus on what's ahead! Don't lose hope, ok?

[harini]

mathsparks:

Hey studentabc,

don't let the maths paper affect you. Stop checking answers already! Stay away from this forum..go focus on yr science. Shoo!!

Well said Mathssparks - GO and study, dont bother abt the Maths paper - thats already OVER ...

[MrsLow]

meyya:

mathsparks:

haha I was wondering also. The only post that says Maths is easy..

my girl also told the maths is very difficult and time is not enough to do.

paper 1 can. paper 2 hard lah

now... the ministry wants our children in Primary to know the topic well and knows the exact application...

Frankly speaking ... (personal opinion only), the Jim and Ken questions many assessment book came out similar questions already. The ministry probably wants the students to know the concepts rather than memorise steps and technique. As for the meilin speed questions... the formula of speed/Distance and Time must be clearly known... on top of that I see it as more of a rate question.

Devi and Raj is an old PSLE questions also...
pardon me if you think I am wrong...this is purely what I saw after knowing and doing many PSLE questions.

infact since the introduction of calculators...it is easier to combine model illustration with algebra to solve difficult questions.

[kiasipluskiasu]

hmmm...anyone remembers the question and answer for the pyramid question???if i remember clearly, its question7, the one on which net cannot be formed into the 'pyramid shown above'. Paper 1, Booklet A (MCQ question) :?: :? :? Pls help.Thanks.[/img]

[Tang]

Guan Hui:

Hello this is what I get from the channelnewsasia forum. I am a tuition teacher who has students taking PSLE so I am quite concern too. Below are the questions and the suggested answers I provide.


PSLE Maths - some of the questions
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? Ans: 11.06am

Suggested Answer:
3.5 x 2 = 7km(how much ahead is mei if she keep cycling when Lin finish the race)

speed= 20km/h
7km= 7/20 X 1
=0.35 hr
=21 mins (time needed to be 7km ahead for mei)
Time when Lin complete the race = 10.45am+ 21mins
= 11.06am




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? Ans: 960

Suggested Answer:
5/6 of chocolate cookie = 5/6 x 3/4
= 5/8 of total cookie (SOLD)
Faction of cookie sold = 1- 1/5
=4/5
Fraction of Almond cookie Sold = 4/5 - 5/8
= 7/40(SOLD == 210 almonds)
4/5= 32/40

7units =210 almonds
32 units = 32/7 x 210
= 960 cookies

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?. Ans: 68 sweets

Suggested answer:

Jim Ken
sweet : Choco Sweet : Choco
1Junit : 7Junits 1Kunit: 4Kunits
1Junit+12 : 7Junits 1Kunit: 4Kunits +18 (before eating the sweets and the chocolates)

Since at the beginning they have the same number of sweets and chocolates.
1Junit + 12 = 1Kunit
4Junits +48 = 4Kunits
4Junits + 66 = 4Kunits +18 = 7Junits
3Junits= 66
1Junit= 22
Number of sweets Jim recieved at the beginning : 22 +12 =34 sweets
Number of sweets Ken buy : 34 +34 =68 sweets
(Regret cant show in model)

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. Ans: 71 puff

Suggested Answers:
3 puffs : $0.80 x 3 =$2.40
4th puff: $0.80 / 2 =$0.40
1 set of 4 puffs cost: $2.40+$0.40=$2.80
Number of sets the customer can buy with $50: 50/2.8=17 sets and $2.40 left
Number of puffs $2.40 can buy: $2.40/$0.80 = 3puffs
Number of puffs in 17 sets: 17x 4 = 68 puffs
Total number of puffs: 68 +3=71 puffs

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? Ans: 345

Suggested Answers:
String of 1 big balloon: 90cm/2 = 45cm
String of 1 small balloon: 120cm/5 = 24 cm
difference in the length of string: 45-24=21 cm
how much longer if they have the same number of big balloons and small balloons: 105(small balloons more) x 24= 2520 cm
The number of big balloons that will cause this difference: 2520/ 21 = 120
Number of big balloons: 120 balloons
Number of small balloons 120+105=225 balloons
Total: 120+225= 345 balloons

This is my 10cent worth of solution hope it helps to further confirm your children answers. Anymore enquires about maths you can call me at 94503822=) I will gladly assist you.
Good luck to all those children taking science and higher chinese next week=)

Hi tutor,

\"Time when Lin complete the race = 10.45am+ 21mins
= 11.06am\"

When in P6, I was deducted 1 mark for mixing Time and Duration. Hence you may want to advise your students to use timeline.

For the balloon question, there has been a debate over 211 and 345. Apparently most P6 students do not seem sure which is correct. Do you happen to have the picture of the arrangement of the balloon from your student?

[Tang]

MrsLow:

now... the ministry wants our children in Primary to know the topic well and knows the exact application...


Frankly speaking ... (personal opinion only), the Jim and Ken questions many assessment book came out similar questions already. The ministry probably wants the students to know the concepts rather than memorise steps and technique. As for the meilin speed questions... the formula of speed/Distance and Time must be clearly known... on top of that I see it as more of a rate question.

Devi and Raj is an old PSLE questions also...
pardon me if you think I am wrong...this is purely what I saw after knowing and doing many PSLE questions.

infact since the introduction of calculators...it is easier to combine model illustration with algebra to solve difficult questions.

This year P6 students have an disadvantage of not being able to use the time saved in Paper 1 for Paper 2. It will be very stressful. I doubt I will be able to get the answer for the speed question under the same examination condition.

[Michael.012516 J.012516 Jackson]

kiasipluskiasu:

hmmm...anyone remembers the question and answer for the pyramid question???if i remember clearly, its question7, the one on which net cannot be formed into the 'pyramid shown above'. Paper 1, Booklet A (MCQ question) :?: :? :? Pls help.Thanks.[/img]

The question is to find the net that do not form the pyramid, Ans: 2

[LR_12_3008]

Michael. J. Jackson:

The question is to find the net that do not form the pyramid, Ans: 2

No, the answer is 4.

[david59]

MrsLow:

infact since the introduction of calculators...it is easier to combine model illustration with algebra to solve difficult questions.

Personally, if I had my way I would rather the kids not use calculator until they are in secondary school. Why? Those PSLE questions could easily be done without the use of a calculator.Besides, many students have become too dependent on the calculator. Let me explain. I work with the Pri sixers in the student care centre and these are some of my observations.
For example, what is the sum total of 1+2+3+4 ... +20.
The right approach is to use Heuristic approach of adding 1+20=21, 2+19=21. Therefore, 1 to 20 can be grouped into 10 sets of every 2 numbers that adds up to 21. Thus the total sum is 21 x 10 = 210.
However, the lazy approach is to simply use the calculator and add 1+2+3+4 all the way to 20 and bingo! the answer 210 appears before your eyes.
Another bad habit I have discovered among some students is that when they are not sure whether they should use multiplication or division, or which set of numbers to divide or multiply with, they simply use the calculator to try and try until they finally come up with an answer that seems reasonable.
What I worry is that the not so smart kids are slowly abandoning the analytical approach to solving questions by relying too much on the calculator to do 'try here, try there' method until they feel that they have got a reasonable answer.

Any parent feels that your child is like what I discuss?