Q&A - PSLE Math

[snowman.022851697]

>Tianzhu: Yes, most of my friends cant even form a basic equation. As for me, i’m especially careless when using algebra and end up using a lot of correction tape.

[tianzhu]

snowman.697:

>Tianzhu: Yes, most of my friends cant even form a basic equation. As for me, i'm especially careless when using algebra and end up using a lot of correction tape.

Hi snowman.697

Use the method a student is comfortable with.That's the way to go.

Wishing you the very best for PSLE 2010.

Best wishes

[ABCDE]

tianzhu:

Hi ABCDE


Thank you for sharing.It's always delightful to see new volunteers in this thread.

You are able to work with algebra manipulation comfortably .For a P6 student, it’s a commendable effort.

Just curious, where did you learn your problem solving technique from? Is it from school or external tuition?

Your answers are correct.

You should do well for PSLE Maths.

Best wishes

Thank u very much Uncle. This really gives me a satisfaction tht i am practising in the right way.Your words really gives me the boost i needed.
Algebra skill was first introduced by my mum. But i got interested in it after cing Dharma uncle solving most of the problems using Algebra .
I am weak in model interpretation, but became good in ALgebra. My school never taught problem solvings thru algebra.
Hence, 10 % credit goes to my mum and 90% to Dharma Uncle. Thank u Dharma Uncle.
After cing yr way of problem solving using Models i'm really amased.Developing interest in tht too. A big thank u to u too uncle.
PS:From P1 until now i had not gone to any tutions for any subjects.

THANK U TO ALL CONTRIBUTORS OF MATH GURU.

[tianzhu]

Hi ABCDE


Good Morning

Your mum must be very happy. You are an independent learner.

Wishing you the very best for PSLE 2010.

Best wishes

[Dharma]

Hi ABCDE,


It is surely nice hear that our contributions here had inspired you. Keep up the good work and my best wishes to you for PSLE.

[Dharma]

kancheongmum:

Hi all just got ACS prelim 2010 from a friend. Suprisingly in my opinion is not as challenging as the others. Came across 2 questions from the paper and like you all to try.


1)Mdm Zhang packed some beads into 14 small boxes and 15 big boxes. There were equal number of beads in each small box and equal number of beads in each big box. Each big box contained 5 more beads than each small box. 3/8 of the beads were packed in small boxes. How many beads were there in each small box? (ans 9)

2) A tank measuring 80 cm by 60 cm by 55 cm was 1/5 filled with water. A tap was turned on to fill it up with water at a rate of 9L per min. Every 30 seconds after the tap was turned on, an iron ball with a volume 500 cm3 was dropped into the tank. How many iron balls would there be in the tank when the water level reached the brim? (ans 42 iron balls)

Q1)

1p = 1u + 5
14(1u)/15(1p) = 3/5
70u = 45p
70u = 45(1u + 5)
25u = 225
1u = 9 (No. of beads in each small box)

Q2)

Amt of volume required for water level to reach the brim
= 4/5 x 80cm x 60cm x 55cm
= 211200cm2

Every 30 secs (1/2 min)
Additional volume = (9000cm3 x ½ min) + 500cm3 = 5000cm3

211200cm3 divide by 5000cm3 = 42.24

When water level reaches the brim; there would be 42 iron balls in the tank already.

[Vanilla Cake]

Dharma:

kancheongmum:

Hi all just got ACS prelim 2010 from a friend. Suprisingly in my opinion is not as challenging as the others. Came across 2 questions from the paper and like you all to try.


1)Mdm Zhang packed some beads into 14 small boxes and 15 big boxes. There were equal number of beads in each small box and equal number of beads in each big box. Each big box contained 5 more beads than each small box. 3/8 of the beads were packed in small boxes. How many beads were there in each small box? (ans 9)

2) A tank measuring 80 cm by 60 cm by 55 cm was 1/5 filled with water. A tap was turned on to fill it up with water at a rate of 9L per min. Every 30 seconds after the tap was turned on, an iron ball with a volume 500 cm3 was dropped into the tank. How many iron balls would there be in the tank when the water level reached the brim? (ans 42 iron balls)

Q1)

1p = 1u + 5
14(1u)/15(1p) = 3/5
70u = 45p
70u = 45(1u + 5)
25u = 225
1u = 9 (No. of beads in each small box)

Q2)

Amt of volume required for water level to reach the brim
= 4/5 x 80cm x 60cm x 55cm
= 211200cm2

Every 30 secs (1/2 min)
Additional volume = (9000cm3 x ½ min) + 500cm3 = 5000cm3

211200cm3 divide by 5000cm3 = 42.24

When water level reaches the brim; there would be 42 iron balls in the tank already.

http://www.onsponge.com/forum/35-thinkingmathonsponge/5169-acs-2010-p6-prelim-maths-paper-2.html for the above 2 questions from ACS (P) 2010 P6 Prelim Maths Paper 2.

VC's mum

[pecalis]

tianzhu:

Hi


You may wish to try this interesting speed question.

At 0954 Mary left Everton Park and cycled towards Serene Park while Joy left Serene Park and cycled towards Everton Park. At 1004, the two cyclists passed each other. 5 minutes later, Mary reached Serene Park but Joy was 780 m from Everton Park.

(a) At what speed were the two cyclists approaching each other?
(b) Find the distance (in km) between Everton Park and Serene Park.

Best wishes

Mary took 10 mins to meet Joy and another 5 mins to complete the journey.
That is, she took 15 mins to complete the journey and at meeting point, she would have travelled 2/3 of the distance.
Joy took 10 mins to complete 1/3 of the distance.
Ratio of distance of Mary : Joy = 2 : 1 = 6 : 3
Mary completed 6 units in 15 mins but Joy has another 3 units to go.
3u = 780m
1u = 260m
(b) Total distance between the 2 parks = 6u = 6x260 = 1560m = 1.56km

(a) Mary's speed = 1560/15 = 104m/min
Joy's speed is half of Mary's, = 52m/min

[tianzhu]

Hi


You may wish to work on this question.

James had some money in his wallet with values between $60 to $150. If he buys the maximum number of water bottles he can afford at $7 each, he will have $1 left. If he buys the maximum number of towels at $9 each, he would have $3 left. What is the actual amount James had?

Best wishes

[ABCDE]

Dharma:

Hi ABCDE,


It is surely nice hear that our contributions here had inspired you. Keep up the good work and my best wishes to you for PSLE.

Thank u very much Uncle Dharma n Tianzhu 4 your wishes