Q&A - PSLE Math

[Dharma]

tianzhu:

To the best of my knowledge, the proportion (ratio) way of solving speed problems is not taught in primary maths.

Hi Tianzhu,

The ratio method was introduced during enrichment class in my daughter's school.

[tianzhu]

Dharma:

tianzhu:

To the best of my knowledge, the proportion (ratio) way of solving speed problems is not taught in primary maths.

Hi Tianzhu,

The ratio method was introduced during enrichment class in my daughter's school.

Hi Dharma

Thank you for your clarification.It may be taught to those involved in competition Maths and not to mainstream students.

Besides proportion mehod, we can also use logic reasoning to solve NY SA2 Q48.It's a little more tedious as compared to proportion method.

[Tang]

Drdj:

Hi there,


Could you help me to solve this sum?
Please take note - we cannot use Pythagoras' Theorem, since P6 students do not learn that.

Thanks in advance
http://www.postimage.org/

2 Unshaded Sectors = Big Semicircle - Triangle

Area = Big Semicircle + Medium Semicircle + Small Semicircle - 2 Unshaded Sectors

= Big Semicircle + Medium Semicircle + Small Semicircle - Big Semicircle + Triangle

= Medium Semicircle + Small Semicircle + Triangle

= 1/2 x 3.14 (8 x 8 + 6 x 6) + 1/2 x 12 x 16

= 253 cm2

[Dharma]

tianzhu:

Hi Dharma


Thank you for your clarification.It may be taught to those involved in competition Maths and not to mainstream students.

Besides proportion mehod, we can also use logic reasoning to solve NY SA2 Q48.It's a little more tedious as compared to proportion method.

Hi Tianzhu,

Both my kids are from the mainstream.

In PSLE, there is NO restriction on the method used to solve a problem. The impt thing is the child solves the maths problem in the way he/she is most comfortable with

[tianzhu]

Hi Dharma


I agree that students should use the method he/she is most comfortable with to solve a problem. After all, he/she will be taking the exam alone.

Just curious, you’ve mentioned about enrichment classes in your child’s school, are these for selected pupils only?

[Dharma]

edanson:

Hello,

anyone can help :

Container A contains 250 red marbles and 200 blue marbles.
Container B contains 600 red marbles and 150 blue marbles.
How many red and blue marbles must be moved from container A to container B such that 25% of the marbles in container A and 75% of marbles in container B are red?

Hi edanson,

Hope this helps

http://www.postimage.org/

[Dharma]

tianzhu:

Hi Dharma


Just curious, you’ve mentioned about enrichment classes in your child’s school, are these for selected pupils only?

Yes, they are for all pupils in the top 2 classes plus pupils talented in maths from the remaining classes

[James Ang]

There are 1000 lockers in a school with 1000 students. The first student opens all the lockers. The second student closes lockers 2,4,6,8,10 till 1000. The third student changes the state (close opened ones and open closed ones) of lockers 3,6,9,12 till 1000 . The fourth student changes the state of lockers 4,8,12,16 till 1000. How many lockers are opened in the end?

[enoawng]

Mr Ng bought three times as many badges as toy cars and spent $144 in total. He spent $84 more on toy cars than on badges. Given that a toy car cost $10.4 more than a badge, what was the cost of the bagde?

[Tang]

James Ang:

There are 1000 lockers in a school with 1000 students. The first student opens all the lockers. The second student closes lockers 2,4,6,8,10 till 1000. The third student changes the state (close opened ones and open closed ones) of lockers 3,6,9,12 till 1000 . The fourth student changes the state of lockers 4,8,12,16 till 1000. How many lockers are opened in the end?

http://prischoolmaths.blogspot.com/2008/11/maths-challenging_658.html