Q&A - PSLE Math

[Brenda10]

Belle2011:

Hello,

I need some help on

There were 32 tourists on a bus. 2/5 of the men and 1/4 of the women were from Singapore. The total number of tourists who came from Singapore was 11. How many men came from Singapore?

Model ans given: 8.

Thanks a lot.

Hi, you may want to refer the following link for solution.

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=280&postdays=0&postorder=asc&start=2180

[Belle2011]

Brenda10:

Belle2011:

Hello,

I need some help on

There were 32 tourists on a bus. 2/5 of the men and 1/4 of the women were from Singapore. The total number of tourists who came from Singapore was 11. How many men came from Singapore?

Model ans given: 8.

Thanks a lot.

Hi, you may want to refer the following link for solution.

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=280&postdays=0&postorder=asc&start=2180

Thanks.

[Hifive]

Hi


Just to check with parents and students here : is it ok to use algebra to do problem solving questions at P6 level ?
I've posted this question in the PSLE 2011 thread but thought I would post it here since some parents/students here have already tried doing the 2010 top school papers. One parent has advised to use model method.

Pls advise because all along I thought schools are using the model method / unit transfer method (actually how many methods are there :oops: )?

Thanks in advance.

[tianzhu]

Hi


Algebraic expressions in one variable is covered under the topic of Algebra in P6.
http://www.moe.gov.sg/education/syllabuses/sciences/files/maths-primary-2007.pdf

The question is after learning Algebra in P6, is a student fully equipped with the skills to cope with word problems using Algebra (taught within syllabus)?

Without going beyond the syllabus, can a student use Algebra effectively to solve word problems ?

Do students need to accelerate their learning of Algebra through external courses (tuition/enrichments) or parents to enable them to use Algebra to solve word problems ?

Every child is unique, they have different leaning abilities. Not every child has the luxury of additional tuition.

Let the child decides, the golden rule is to use whichever method a child is comfortable with to solve a question.

Here’s a reply from MOE on Different Approaches Taught for Mathematics Techniques
http://www.moe.gov.sg/media/forum/2007/20070217.htm

Merry Christmas and a Happy New Year.

Best wishes

[Hifive]

Hello tianzhu


Many thanks for your reply to my query and the MOE website link you have indicated.

Wishing you and your family a MERRY CHRISTMAS AND A HAPPY NEW YEAR!

[tianzhu]

Hi Hifive


You're welcome.

If you keen to find out more about Unit Transfer Method, you may refer to this link.
http://www.mathsheuristics.com.sg

This is a good link to find out more about MD.
http://www.aaasurvey.com/tutor_html/bottom_create5_all.html

Best wishes

[Hifive]

Hello tianzhu


Thank you for your advice!

[Belle2011]

Hi,

I need some help again.

(1) Dolly had 80 more stickers than Jenny. Dolly gave 25% of her stickers to Jenny. Jenny in return gave 60% of her stickers to Dolly. In the end, Dolly had 100 stickers more than Jenny. How many stickers did Dolly have at first?

(model ans: 116 stickers)

(2) Julian had 300 more cards than Faizal. Julian gave 3/5 of his cards to Faizal. Faizal then gave 1/4 of the total number of what he had then to Julian. In the end, Faizal had 300 more cards than Julian. How many cards did Julian have at first?

(model ans: 1125)

(3) Tanks X and Y are each filled with some water. If water from Tank Y is poured into Tank X until the water in Tank X reaches the brim, there will be 8 litres of water left in Tank Y. If water from Tank X is poured into Tank Y until the water in Tank Y reaches the brim, there will be 26 litres of water left in Tank X. The ratio of the volume of Tank X to the volume of Tank Y is 5:3. How many more litres of water are needed to fill both tanks to their brim?

(model ans: 19 litres)

Thanking you in advance.

[Brenda10]

Belle2011:

Hi,

I need some help again.

(1) Dolly had 80 more stickers than Jenny. Dolly gave 25% of her stickers to Jenny. Jenny in return gave 60% of her stickers to Dolly. In the end, Dolly had 100 stickers more than Jenny. How many stickers did Dolly have at first?

(model ans: 116 stickers)
Thanking you in advance.

Hi, this question was from Nan Hua 2010 CA1 P2 Q18.

25%= 1/4, 60% = 3/5

1/4=5/20, 3/5 = 12/20
80 x 5/20 = 20, 20 x 12/20 = 12
80 - 20 = 60, 20 - 12 = 8


4u+ 60 + 12 = 100 + 8
4u + 72 = 108
4u = 108 - 72
4u = 36

Dolly: 4u + 80
36 + 80 = 116


Thank you

[Brenda10]

Belle2011:

Hi,

I need some help again.

((2) Julian had 300 more cards than Faizal. Julian gave 3/5 of his cards to Faizal. Faizal then gave 1/4 of the total number of what he had then to Julian. In the end, Faizal had 300 more cards than Julian. How many cards did Julian have at first?

(model ans: 1125)
Thanking you in advance.

Hi, this question was from NY 2010 CA1 P2 Q17.

3/5, 1/4

12/20 , 5/20

300 x 12/20 = 180, 180 x 5/20 = 45
300- 180 = 120, 180 - 45 = 135

2u = 120 + 45 + 300 - 135
2u = 330
1u = 165


Julian: 5u + 300
5 * 165 + 300 = 1125


Thank you