Q&A - PSLE Math

[lizawa]

Hi Tianzhu,


May I ask which school’s paper were these questions from ?

[lizawa]

Q1) There are 85 plates of fried noodle for 80 people. Each adult eats 2 plates of fried noodle and every three children share 1 plate of fried noodle. How many adults and children are there?


Solution:
----------------
Easiest and fastest to solve by algebra.

Let no. of adults be x and no. of children be y

x + y = 80
=> x = 80 -y

2x + 1/3y = 85
2(80-y) + 1/3y = 85

Solve for y and x.
x = 35, y - 45

[lizawa]

Q1) There were some marbles at a shop. The ratio of the number of red marbles to the number of blue marbles was 2:3. When 50 more red marbles and 30 more blue marbles were added, the ratio of the number of red marbles to the number of blue marbles became 5:6. How many marbles were there at first?


Solution:
--------------
Before adding:
Red : Blue
= 2: 3
= 4: 6

After adding, (based on the above ratio)
Red : Blue
= 4u+50 : 6u+30
= 4u+50 : 6(u+5)

The given ratio, after adding is :
Red : Blue
= 5:6

Compare blue ratio, 6(u+5) = 6
hence, red ratio = 5(u+5)

Equate this to the red ratio found earlier.

5(u+5) = 4u+50
5u+25 = 4u +50
u = 25

At first ,
red marbles = 4u = 4 x 25 = 100
blue marbles = 6u = 6 x 25 = 150

[tianzhu]

Stumbled upon this product while surfing, anyone tried it?

Your feedback is appreciated.

http://computertimes.asia1.com.sg/ctkids/story/0,5104,1942,00.html

A virtual guide to PSLE maths
By Chan Lee Shan
Jan 28, 2004
• Miss Karey, PSLE Maths
• $38
• Available from ChithromMedia. Call 6334-2098 or e-mail [email protected]
Overview: This maths CD-ROM is a tutorial program that teaches the core concepts of each unit of the Primary 6 mathematics syllabus in a comprehensive manner.
With a virtual teacher delivering the lecture content, the CD-ROM simulates the classroom environment. The pause, forward and backward options allow users to control the pace of their learning and the software lets users branch out to different sections. In general, clear explanations of ideas and extensive use of diagrams, models and virtual graphics enrich the learning journey.
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At the end of each unit, the program tests the user's understanding through drill and practice exercises. Various question formats like recall questions and word problems are included in the exercises. Hints are provided to assist the user when necessary.
The user is allowed three tries before the solution to each problem is revealed. This aside, 3D animation is used to explain abstract ideas.
Once the user completes a series of 20 questions of varying difficulty levels for a unit, a score with a comment on his performance is reflected in an individualised report card.

Find out how mathematics can be fun.
Teachers and parents can then use the scoring device to track the user's progress and obtain feedback.
After the arduous tasks of going through the lectures and exercises, the user can indulge in an entertaining and interactive game that combines adventure and intellect.

The user's goal is to compete against time and solve problems of different themes to progress through the stages. The user has to cross several obstacles in different scenarios.
The game is motivating through the good use of animation and graphics. However, some of the tasks presented may be too challenging for Primary 6 pupils.
Reviewer's comments: This software serves its purpose as a teaching tool for teachers to deliver the fundamental lesson content.
The smarter pupils can master the concepts independently through this software and time can be spent on more advanced ideas.
Chan Lee Shan teaches Primary 6 Maths at a local school.

[lizawa]

tianzhu:

2) Susan went shopping with a sum of money. She spent 0.5 of her money plus $5 on a handbag. She then spent 0.5 of the remaining money plus $3 on a pair of sunglasses. Finally she spent 0.5 of what was left plus $2 on an umbrella. She was then left with $1.50. How much money did she have at first?

This one is not difficult, but needs to work from the last part of the question. Can draw a big bar and divide according to the question to visualize better.

$1.50 -----> (+2) = $3.50 ----> (x2) = $7.00 ---> (+3) = $10 ----> (x2) = $20 ----> (+5) = $25 ----> (x2) = $50.

[lizawa]

tianzhu:

3) There are 600 children in Team A and 30% of them are boys.
There are 400 children in Team B and 60% of them are boys.
After some children are transferred from Team B to Team A, 40% of the children in Team A and 60% of the children in Team B are boys.
How many children are transferred from Team B to Team A?

This is a tricky one. The key is : The total number of boys before and after the movement is the same.

Total boys = (30% x 600) + (60% x 400) = 420
Total girls = (70% X 600) + (40% x 400) = 580
Total = 1000

After movement, in team A
Boys : Girls
= 4 : 6
= 2 : 3

In team A, there are 5units of children.
In team B, there will be 1000 - 5 units of children.

Team B ratio,
Boys : Girls
= 6 : 4
= 3 : 2
= 3/5(1000 -5u) : 2/5(1000 -5u)


2u of boys in team A + 3/5(1000 - 5u) of boys in team B = 420

2u + 600 - 3u = 420
1u = 180

# of boys in team A after movement = 2u = 360
# of girls in team A after movement = 3u = 540
Total in team A = 900.

# of children transferred from team B to team A = 900 - 600 = 300.

[tianzhu]

lizawa:

Hi Tianzhu,


May I ask which school's paper were these questions from ?

Sorry, lizawa

The person who passed them to me cannot remember the source.Anyway, what is more important is that these questions helped to sharpen our kids' skills in answering Maths questions.Hope fellow members will find them useful.

Best Wishes

[ChiefKiasu]

Looks good! Here's a trial sample of the CDROM:

http://www.misskarey.com/misskarey.htm

I'm ordering one. Will do a review subsequently.

[tianzhu]

Why do parents and pupils have problems with the PSLE Maths paper?


Mr Tan Yap Kwang, chief executive of the Singapore Examinations and Assessment Board (SEAB), offers this explanation: 'For Maths, if you don't understand the question or the concept tested, you cannot even start solving the sum. For English or Mother Tongue, you can always guess an answer.'

What’s your take?

http://www.straitstimes.com/print/Free/Story/STIStory_169062.html
Oct 21, 2007
At sixes and sevens over PSLE Maths

AS FAR as parents and pupils are concerned, PSLE Maths papers often just don't add up.
Howls of outrage greeted this year's test, with mums and dads fuming and some pupils in tears outside the exam room.
Parents also cried foul in 2005, after a flawed question slipped into the paper.
In 2000, about 25 angry parents called The Straits Times to complain about the paper being too difficult.
And in 1992, the Ministry of Education was criticised when parents raged about tough questions.
It all looks like a standard formula: tricky questions plus nervy pupils and expectant parents multiplied by exam pressure equal tears and ill temper.
Why do parents and pupils have problems with the PSLE Maths paper?
Mr Tan Yap Kwang, chief executive of the Singapore Examinations and Assessment Board (SEAB), offers this explanation: 'For Maths, if you don't understand the question or the concept tested, you cannot even start solving the sum. For English or Mother Tongue, you can always guess an answer.'
A maths teacher, who declined to be named, said: 'Maths is the one subject pupils can possibly score 100 marks for, unlike English. So it devastates them when they cannot do well.'
Mr Tan, who feels parents are over-reacting, said this year's paper was no tougher than in other years. 'Sometimes pupils have very high expectations for themselves. Not being able to answer one question is like the end of the world.'
Ten parents and former teachers complained to The Straits Times Forum page that some sums were not in the syllabus.
Mr Tan said the PSLE must differentiate between pupils of different abilities: 'It'd be a problem if 30 per cent of the cohort scores full marks. Then how do you differentiate between the average student and the brightest of the lot?'
Ten teachers told The Sunday Times they had never seen so many pupils crying after a PSLE paper.
One admitted that she needed a calculator to solve one of the sums. Pupils are not allowed to use them.
A teacher was called into the exam hall after a top pupil broke down and wanted to quit. But Mr Norman Tien, a PSLE Maths trainer, said: 'Most students are drilled to do past exam papers. If they come across a question they've never seen before, they'll think it's difficult.'
At least 95 per cent of a cohort should be able to tackle the basic questions, Mr Tan said, while the last few 'challenging' sums are aimed at the brighter ones.
Pupils should not fret if they cannot answer some questions. Mr Tan said: 'You don't need to answer every one correctly to get an A*.'
[email protected]

[tianzhu]

3) Daniel has $160 more than Alex. After giving 1/10 of his money to Alex, he now has 3 times as much money than Alex. How much money do they have in the first place?



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