Q&A - PSLE Math

[Lynn2]

Hi Tianzhu and all,


Thanks for all the helps.I will walk through with all the various way that you have provided and sure hope can clear that block in her mind.

Will post again should I failed to accomplish the mission...

Cheers
Lynn2

tianzhu:

Hi Lynn2

Ok, now the solutions to one of your earlier “coins questions”.

Usually, I solve it making some assumption.

An alternative solution is MD. It hinges on “number and value” of the different coins.
Another way is to use the “Number* Value Method by working in tabulated form. This is a tweaked version of the usual “Number*Value’ table.

Hope this helps.

Best wishes

http://farm6.static.flickr.com/5014/5557734869_1bdc3c4e23_z.jpg\">

[Lynn2]

Hi Tianzhu,


My girl is so impressed with your first model, and say wow he so smart.

But, when he looked at your xie ming ming question, try to follow your first model, and says cannot leh...she can only says why xie ming ming...the show.....

Here it goes for your question and asked can u draw it like your first model as below.Thanks.

Xie Ming Ming paid $36 for some 10 cents and 20 cents stamps. She bought 4 times as many 10 cents stamps as 20 cents stamps. How many stamps did she buy altogether?


cheers Lynn2

tianzhu:

Hi Lynn2

Ok, now the solutions to one of your earlier “coins questions”.

Usually, I solve it making some assumption.Pretend that the number of $1 coins is equal to the number of 50 cents coins, you'll have (17*1) + 15.50 more of value in Box B.

An alternative solution is MD. It hinges on “number and value” of the different coins.
Another way is to use the “Number* Value Method by working in tabulated form. This is a tweaked version of the usual “Number*Value’ table.

Hope this helps.

Best wishes

http://farm6.static.flickr.com/5014/5557734869_1bdc3c4e23_z.jpg\">

http://farm6.static.flickr.com/5062/5557734951_9232b0d90a_z.jpg\">

[tianzhu]

Hi Lynn2


For the question on Xie Ming Ming, it’s more appropriate to use “Number* Value’’ or "Grouping"

Try to look at the second MD, the one with the flower.

Please refer to my earlier post @Fri Mar 25, 2011 11:16 am

Best wishes

[jieheng]

Xie Ming Ming paid $36 for some 10 cents and 20 cents stamps. She bought 4 times as many 10 cents stamps as 20 cents stamps. How many stamps did she buy altogether?


10 cents [][] [][]

20 cents []

One set consists of 5 stamps (4 ten cents and 1 twenty cents)

Value of one set of stamp = 4 * 0.1 + 1 * 0.2 = 0.6

No. of sets of stamps = 36 / 0.6 = 60

Total no. of stamps = 60 * 5 = 300 stamps (Ans)

[ozora]

PSLE Question:

Q1) 6/14 of chairs in a hall are in rows of 13.
Half of the chairs are in rows of 7. There are 112 more chairs in the rows of 7 . The rest are stacked up. Find the total number of chairs.

Q2) Shop A has 156kg of rice while shop B has 72 kg of rice. After both shops sold an equal amount of rice, the ratio of amount of rice in Shop A to amount of rice in Shop B is 4:1. Find the amount of rice sold.

[tianzhu]

ozora:

PSLE Question:

Q1) 6/14 of chairs in a hall are in rows of 13.
Half of the chairs are in rows of 7. There are 112 more chairs in the rows of 7 . The rest are stacked up. Find the total number of chairs.

Q2) Shop A has 156kg of rice while shop B has 72 kg of rice. After both shops sold an equal amount of rice, the ratio of amount of rice in Shop A to amount of rice in Shop B is 4:1. Find the amount of rice sold.

Hi ozora

Good Morning

PSLE questions?

Are these questions taken from the PSLE booklets from authorised publishers?

If not, take into consideration that the questions may be worded differently from the actual PSLE questions. Students may not be able to memorise the questions in the exact manner they are asked under examination conditions.

Here’s the solution, you may use MD.
Due to time constraints, I shall only give you some pointers.

Q1

Draw a bar, divide into 14 units.
6 units ------- rows of 13
7 units ------- rows of 7
1 unit ------- 112
14 units ------ 112*14 -------- 1568

In this question, there are no remaining chairs left to be stacked up.Please check the numbers in your question again.Unless the information is intentionally given so as to confuse students.I guess this is not the actual PSLE question.


Q2

Since both shops sold an equal amount of rice, the difference remains the same before and after.

Difference ----- 156 – 72 ------ 84

4 -1 ------3

3 units ------- 84
1 unit ------- 28

72 – 28 ------- 44

Amount of rice sold by each shop ----- 44kg

Find the amount of rice sold --- Does it refer to the amount sold by individual shop or in total? Again, I guess this is not the actual PSLE question.

kiasu lah, give answers to cover all angles

Shop A ----- 44 kg
Shop B ----- 44 kg

Total amount sold ----- 88 kg

Hope this helps.

Best wishes

[ozora]

tianzhu:

ozora:

PSLE Question:

Q1) 6/14 of chairs in a hall are in rows of 13.
Half of the chairs are in rows of 7. There are 112 more chairs in the rows of 7 . The rest are stacked up. Find the total number of chairs.

Q2) Shop A has 156kg of rice while shop B has 72 kg of rice. After both shops sold an equal amount of rice, the ratio of amount of rice in Shop A to amount of rice in Shop B is 4:1. Find the amount of rice sold.

Hi ozora

Good Morning

PSLE questions?

Are these questions taken from the PSLE booklets from authorised publishers?

If not, take into consideration that the questions may be worded differently from the actual PSLE questions. Students may not be able to memorise the questions in the exact manner they are asked under examination conditions.

Here’s the solution, you may use MD.
Due to time constraints, I shall only give you some pointers.

Q1

Draw a bar, divide into 14 units.
6 units ------- rows of 13
7 units ------- rows of 7
1 unit ------- 112
14 units ------ 112*14 -------- 1568

In this question, there are no remaining chairs left to be stacked up.Please check the numbers in your question again.Unless the information is intentionally given so as to confuse students.I guess this is not the actual PSLE question.


Q2

Since both shops sold an equal amount of rice, the difference remains the same before and after.

Difference ----- 156 – 72 ------ 84

4 -1 ------3

3 units ------- 84
1 unit ------- 28

72 – 28 ------- 44

Amount of rice sold by each shop ----- 44kg

Find the amount of rice sold --- Does it refer to the amount sold by individual shop or in total? Again, I guess this is not the actual PSLE question.

kiasu lah, give answers to cover all angles

Shop A ----- 44 kg
Shop B ----- 44 kg

Total amount sold ----- 88 kg

Hope this helps.

Best wishes

thanks for the guide. The questions were asked in 2007. It was stated in the The Straits Times as indicated by the school teacher in the worksheet. So I am not sure was it correct or not?

[tianzhu]

ozora:

The questions were asked in 2007. It was stated in the The Straits Times as indicated by the school teacher in the worksheet. So I am not sure was it correct or not?

Hi ozora

Good Morning.

For the actual PSLE questions, you may refer to this book, PSLE Maths Exam Question 2006-2010.

You should be able to get a copy from schools or Popular bookstores
PSLE Past Year Questions of past 5 years are available from the following publishers.
http://www.seab.gov.sg/psle/pslePublications.html

For more PSLE questions, please refer to this link.
http://blogs.blogtv.sg/starbloggers/tag/math-quiz/

Best wishes

[bellerina]

Dear all,


Please help on these challenge questions without algebra. :?:

1) Aini, Bala, Caili & David went to buy a wedding gift for Ms Tai. They shared the cost equally among themselves. However, David forgot to bring money. So his friends paid for the gifts first.

Caili: I paid 3/7 of the amount Aini & Bala paid.
Aini: I paid $8 more than Bala.

The next day, David returned $3 to Caili & some money to Aini & Bala. How much money did David return to Bala & Aini?

2) Nat & Don collected some 'hongbao' money. If Nat spent $10 each day & Don spent $20 each day, then Nat would have $250 left when Don had spent all his money. If Nat spent $20 each day & Don spent $10 each day, then she would have $10 left when he had spent all his money. How much money did Nat receive?

3) Sue & Nur each earned some money during the school holidays. If Sue spent $40 each week & Nur spent $120 each week. Sue would have $720 left when Nur had spent all her money. If Sue spent $120 each week and Nur spent $40 each week, Sue would have $80 left when Nur had spent all her money. How much did Sue earn?

4) Roy & Qing had $282. Qing had $4 less than Roy. Qing spent half as much as Roy & was left with twice as much money as Roy. How much did Qing spend?

5) Yon had 255 red and white fishes altogether. There were 15 fewer white than red. He sold half as many white as red and was left with twice as many white as red. How much red fishes did he sell?

Thanks much!!!

[Cheerfuldad]

Hi all,


Please help!

Q. The ratio of Kailing’s weight to Valerie’s weight is 7:9. If Kailing and Valerie gained some wieght in the ratio of 2:3, Kailing will weight 5/7 of Valerie’s weight. If their total weight was 80 kg at first, how much heavier is Valeria than Kailing now?

Thank you.