Q&A - PSLE Math

[tianzhu]

Hi Hifive


This question touches on simultaneous concept. There are two unknowns and two equations.

Students who are familiar with simultaneous equations may use it solve the problem.

Those who are not, don’t worry too much, you can still get around the problem by solving the equations pictorially. Alternatively, you may also solve it by representing the units and parts by letters of the alphabet or simply using units and parts.

Hope this helps.

Best wishes

http://farm4.static.flickr.com/3079/5819760157_cfb63b3d54_z.jpg\">

[MathIzzzFun]

PiggyLalala:

MathIzzzFun:

[quote=\"Hifive\"]Hi


Maths problem - pls help...

Terry and John went shopping with a total of $198. Terry had $10 more than John. Terry spent 25% as much money as John. After which, he had twice as much money as John.
a) How much money did Terry bring for shopping?
b) How much money had Terry left after shopping?

Kindly help. Thanks in advance!

Hi

here's the model approach

http://www.flickr.com/photos/62167097@N02/5820245316/in/photostream
cheers.

Thanks for the model approach. I have tried to draw the model but not successful. Though my model is same as yours, I failed to see that 1big block = 3u + 10. [/quote]hi

u r welcome

Usually, moving the blocks around will help to \"see\" for example :

http://i52.tinypic.com/2sb3ac8.jpg\">

cheers.

[PiggyLalala]

tianzhu:

Hi Hifive


This question touches on simultaneous concept. There are two unknowns and two equations.

Students who are familiar with simultaneous equations may use it solve the problem.

Those who are not, don’t worry too much, you can still get around the problem by solving the equations pictorially. Alternatively, you may also solve it by representing the units and parts by letters of the alphabet or simply using units and parts.

Hope this helps.

Best wishes

http://farm4.static.flickr.com/3079/5819760157_cfb63b3d54_z.jpg\">

:thankyou: for the alternative 'model' approach. Yours is easy to understand because it is just simultaneous questions in pictorial form.
But not all word problems can use such pictorial simultaneous equations right? How to know which one can, and which one cant?Sorry.. i ask many questions again. Sorry and thanks for your solution and time.

[PiggyLalala]

hi


u r welcome

Usually, moving the blocks around will help to \"see\" for example :

http://i52.tinypic.com/2sb3ac8.jpg\">

cheers.[/quote]
yup... i think i need to practise more on this shifting around of block so that i can 'see'. thank you.

[corneyAmber]

I agree with you mathizzzfun about moving the blocks around and most times even hand drawn pictures can still roughly deduce. However in this case, not so clear so under exam conditions, if there are no perfect tools to produce the diagrams perfectly, it would be difficult to deduce the 10 per your diagram. Maybe you can help to think further how it can be deduced if diagrams cannot be perfectly drawn. thank you.

[tianzhu]

adanial:

Hello, pls help with the question below....thank you


Question 1
Loyang electronic store sold television sets, fans and washing machines.
2/5 of the items in the store were television sets. 12.5% of the remainder were fans and the rest were washing machines. During a sale held in december, the number of televsion sets sold to the number of fans sold to the number of washing machnes sold was 3:2:4. Altogether 3/4 of the items in the store were sold and $34070 was collected from the sale of all the items.
The table below shows teh average selling price of the 3 items in loyang electronic store :

TV set - $1350
Fan - $102
Washing m/c - $640

How many washing machines were on sale at first ?

Hi

Please help to confirm the numbers which were underlined.

Best wishes

[tianzhu]

PiggyLalala:

:thankyou: for the alternative 'model' approach. Yours is easy to understand because it is just simultaneous questions in pictorial form.
But not all word problems can use such pictorial simultaneous equations right? How to know which one can, and which one cant?Sorry.. i ask many questions again. Sorry and thanks for your solution and time.

Hi PiggyLalala

You're welcome.

Yes, you’re correct to say that one cannot apply SE to all word problems.

MD is one of many problem solving heuristics in the primary maths syllabus, it’s not the only way.

You may use “simultaneous concept” to questions involving two variables scenarios.

Best wishes

[Hifive]

Hi ksi, MathIzzzFun, PiggyLalala and tianzhu


Many thanks for taking your precious time to help me in the understanding of the Maths problem sum.

Really feel so bless for the help from all the experts here.

Have a nice day ahead!

[adanial]

tianzhu:

adanial:

Hello, pls help with the question below....thank you


Question 1
Loyang electronic store sold television sets, fans and washing machines.
3/5 of the items in the store were television sets. 12.5% of the remainder were fans and the rest were washing machines. During a sale held in december, the number of televsion sets sold to the number of fans sold to the number of washing machnes sold was 3:2:4. Altogether 3/4 of the items in the store were sold and $34070 was collected from the sale of all the items.
The table below shows teh average selling price of the 3 items in loyang electronic store :

TV set - $1350
Fan - $102
Washing m/c - $640

How many washing machines were on sale at first ?

Hi

Please help to confirm the numbers which were underlined.

Best wishes

changed 2/5 to 3/5 ** thanks

[corneyAmber]

http://i55.tinypic.com/35bw65i.jpg\">