## Q&A - PSLE Math

Hilizawa wrote:Yes, these are typical P5/P6 questions. Good thing is, when you get to P6, you can use algebra if you wish to.

Q1 can be solved by algebra, model or guess and check. The last method should be least encouraged at this level.

35 adults, 45 children.

Q2 by ratio should be easy enough

8 boys and 12 girls

Q3 by model

Daniel : $200, Alex : $40

I am not sure, but I would think that Q1 and Q2 are 5 mark each and Q3, 4 marks.

So, there are more than 1 way to solve the problems. The child must be good enough to identify the shortest and most accurate way to solve it due the time constraint and pressure during exam.

For the benefits of all members, could you provide the detailed solutions?

# tickets sold by 1 boy : # tickets sold by 1 girl

= 5: 3

ticket sales by 1 boy : ticket sales by 1 girl ( x $5 / ticket)

= 25 : 15

If there are u number of boys,

ticket sales by boys : ticket sales by girls

= 25u : 15 (20 -u)

Difference in ticket sales = 20

25u - 15(20-u) = 20

40u = 320

u = 8

# boys = 8; # girls = 12

Q3 :

Not sure how to draw model here. Need to have before and after model.

Before :

Daniel : 10 units + $160

Alex : 10 units

After :

Daniel : 3 parts

Alex : 1 part

Since Daniel gives 1/10 to Alex, he has given (1 unit + $16) to Alex

In the "After" model,

1 part (for Alex) = 11 units + $16

3 parts (for Daniel) = 9 units + $144 ; ie. 1 part for Daniel is 3 units + $48

2(11units + 16) = 6 units + $96

22 units + $32 = 6 units + $96

16 units = $64

1 unit = $4

At first,

Alex has 10 units = 10 X $4 = $40

Daniel has 10 units + $160 = $40 + $160 = $200.

Not sure how to draw model here. Need to have before and after model.

Before :

Daniel : 10 units + $160

Alex : 10 units

After :

Daniel : 3 parts

Alex : 1 part

Since Daniel gives 1/10 to Alex, he has given (1 unit + $16) to Alex

In the "After" model,

1 part (for Alex) = 11 units + $16

3 parts (for Daniel) = 9 units + $144 ; ie. 1 part for Daniel is 3 units + $48

**The difference is 2 parts**:*this is the key*2(11units + 16) = 6 units + $96

22 units + $32 = 6 units + $96

16 units = $64

1 unit = $4

At first,

Alex has 10 units = 10 X $4 = $40

Daniel has 10 units + $160 = $40 + $160 = $200.

Last edited by lizawa on Mon Jun 02, 2008 9:59 am, edited 1 time in total.

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

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

### A virtual guide to PSLE Maths

Stumbled upon this product while surfing, anyone tried it?

Your feedback is appreciated.

http://computertimes.asia1.com.sg/ctkid ... 42,00.html

By Chan Lee Shan

Jan 28, 2004

• Miss Karey, PSLE Maths

• $38

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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.

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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.

Your feedback is appreciated.

http://computertimes.asia1.com.sg/ctkid ... 42,00.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 purchase@misskarey.com

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.

Advertisement

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.

### Re: P5/P6 - Three more Maths Questions

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.tianzhu wrote: 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?

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