Q&A - PSLE Math

[happyheart]

Dear Tianzhu,

Thanks again for your kind words and advice. In fact, my DS is still in P5. Sorry to have misled you. When I mentioned history, Geography etc, he so happen to be so interested in those subjects that he will reach out on his own to look for books, articles for those information and he remember the info after reading them. It just that for Maths, he can do many sums but still forget how to go about it.

I agree with you. He needs to understand the concept rather than just remembering the formulas. Thanks again for your encouragement. I will try to fine tune the way he approaches Maths.

Have a good day!

[tianzhu]

bbkoala:

Hi


Need help on the following question:

Mrs Tay bought 72 plastic and wooden hangers. Each plastic hanger costs $1.50 and each wooden hanger costs $3.50. She spent $42 more on wooden hangers than plastic hangers. How many wooden hangers did she buy?

DD's teacher's answer is 30.
The steps as follows:
$42/3.50=12, 72-12=60, 60/2=30.

Need help to understand why these steps are taken.

Hi

The answer is correct, but I am still trying to understand the teacher’s logic and steps.

This is a typical question on “Make a Supposition” type of questions.

Maybe, you can try this question. I’ve changed some numbers.

Mrs Tay bought 72 plastic and wooden hangers. Each plastic hanger costs $3 and each wooden hanger costs $5. She spent $24 more on wooden hangers than plastic hangers. How many wooden hangers did she buy?

Best wishes

[Bunny27]

MathIzzzFun:

Bunny27:

I'm not sure about tis question......

Colin and Karin save $2378.1/6 of Colin's savings is $41 more than 1/7 of Karin's savings. Find the ratio of Colins savings to Karin's savings. Express your answer in the simplest form.

TIA

Hi

Karin's savings --> 7 units
Colins savings --> 6 x ( 1 unit + 41) = 6 units + 246

total --> 13 units + 246 = 2378
1 unit --> 164

Colin's savings : Karin's savings
= 6 x 164 + 246 : 7 x 164
= 15 : 14

cheers.[/quot



Thank you

[bbkoala]

Hi Tianzhu


Thanks for your reply.
I managed to get the answer 30 using supposition, after reading your message.

Just can't understand the teacher's logic.
And DD insist it's the correct way (bcos teacher says so) but she can't explain why it's done this way.
This is what's worrying me

[fightingmom]

Hi All,

Please help :stompfeet: :stompfeet:

Jim bought some chocolates and gave half of them to Ken. Ken bought some sweets and gave half of them to Jim.

Jim ate 12 sweets and Ken ate 18 Chocolates. After that, the number of sweets and chocolates Jim had were in the ratio 1:7 and the number of sweets and chocolates Ken had were in the ratio 1:4.

How many sweets did Ken buy?

thanks !!!

[fightingmom]

Hi All,


Please help with the following question:

Jim bought some chocolates and gave half of them to Ken. Ken bought some sweets and gave half of them to Jim.

Jim ate 12 sweets and Ken ate 18 Chocolates. After that, the number of sweets and chocolates Jim had were in the ratio 1:7 and the number of sweets and chocolates Ken had were in the ratio 1:4.

How many sweets did Ken buy?

thanks !!!

[MathIzzzFun]

fightingmom:

Hi All,


Please help with the following question:

Jim bought some chocolates and gave half of them to Ken. Ken bought some sweets and gave half of them to Jim.

Jim ate 12 sweets and Ken ate 18 Chocolates. After that, the number of sweets and chocolates Jim had were in the ratio 1:7 and the number of sweets and chocolates Ken had were in the ratio 1:4.

How many sweets did Ken buy?

thanks !!!

Hi

You may want to look at similar questions in previous posts. Here are two :

http://www.flickr.com/photos/62167097@N02/5932660565/in/photostream

http://www.flickr.com/photos/62167097@N02/6594157121/in/photostream

cheers.

[imacsg]

Can someone help me?


Study the number pattern below carefully.

What is the missing number in the box?

4, 6, 8, 12, 24, 36, ____, 144, 480

Thanks.

[tianzhu]

imacsg:

Can someone help me?


Study the number pattern below carefully.

What is the missing number in the box?

4, 6, 8, 12, 24, 36, ____, 144, 480

Thanks.

Hi

24*4 ------ 96

Missing number is 96

Best wishes

[jessielu]

Need help on below question:


A dictionary cost $11 more than a book.  The book cost $45 more than a magazine.  Mr lee paid a total of $252 for 6 pieces of each item.  What is the cost of a book?

Appreciate the steps to solve this