Q&A - P3 Math

[raysusan]

tianzhu:

raysusan:

can someone help me on this please


jerry bought some posters. he bought 3x as many pcs of poster A as poster C and 2x as many pcs of poster B as poster C. he spent a total of $300 on the posters

a] how many pcs of poster B did he buy
b] how much more did he spend on poster B than on poster A

Hi

I am wondering if there is missing information such as the price of posters in the question.

In order to find out the number of poster B, I think we need to know the per unit cost of the poster.

Best wishes

sorry my bad
post edited

poster A $1.50 poster B $3.00 poster C $4.50

[tianzhu]

raysusan:

can someone help me on this please


jerry bought some posters. he bought 3x as many pcs of poster A as poster C and 2x as many pcs of poster B as poster C. he spent a total of $300 on the posters

poster A $1.50 poster B $3.00 poster C $4.50

a] how many pcs of poster B did he buy
b] how much more did he spend on poster B than on poster A

Hi

One way to solve this question is to use “Grouping”

Consider a group of 3 poster A, 2 poster B and 1 poster C.

3x1.5 --------4.5
2x3 ------- 6
1x4.5 ------ 4.5
Cost for 1 group ------- 15

300/15 ------- 20
There are 20 groups.

Hence, you’ll have
Poster A ------- 60
Poster B ------- 40
Poster C ------- 20

(40x3) – (60x1.5) ------- 30

Best wishes

[wahwah]

Hi ksi,

Thanks for the solution.

[corneyAmber]

wahwah:

Hi ksi,

Thanks for the solution.

:welcome:

[raysusan]

thz u so much tianzhu

:thankyou:

[tianzhu]

raysusan:

thz u so much tianzhu

:thankyou:

Hi

You're welcome.

Best wishes

[peterch]

Deleted

[Champion]

Hi All,

Sorry if what I am asking here has been asked before but I just want to clear some doubts that have been going thru my mind especially this year when DD1 is already P3 (ooops! maybe I am late somewhere in the learning process.... )

I read a lot of postings regarding the \"Model Approach to Problem-solving\" and other Math Heuristics terms! Frankly speaking, I was at a loss when I saw these and asked myself,\" Did I miss out something when DD1 started P1 2 years ago? Am I a late learner that only now then I know of all these GIGANTIC MATHS TERMS?\"

Can anyone advise - if Model drawings are a \"MUST\" moving into upper levels of Maths? What are the other Math Heurisitics method that need to know of to get the Maths Foundation right?

I appreciate and learn a lot of method solving here in this forum; really appreciates many who come forward to share :grphug: :celebrate:

[CoffeeCat]

Champion:

Can anyone advise - if Model drawings are a \"MUST\" moving into upper levels of Maths? What are the other Math Heurisitics method that need to know of to get the Maths Foundation right?

I appreciate and learn a lot of method solving here in this forum; really appreciates many who come forward to share :grphug: :celebrate:

Hi, model drawings is a method that can be used to solve many problems for Singapore's PSLE Maths. However if large numbers are involved \"better methods\" (but based on the same principle) are used sometimes. So yes, it's probably a must for moving to upper primary maths (but some may argue otherwise :scared: )
Math Heuristics are essentially a set of techniques used to solve questions. I believe there is a thin assessment book called Problem-Solving with Heuristics.
Model Drawing can be seen as a heuristic too.
Quoted from moe maths syllabus
\"Thinking skills and heuristics
Students should use various thinking skills and heuristics to help them solve mathematical problems. Thinking skills are skills that can be used in a thinking process, such as classifying, comparing, sequencing, analysing parts and wholes, identifying patterns and relationships, induction, deduction and spatial visualisation. Some examples of heuristics are listed below and grouped in four categories according to how they are used:
•
To give a representation,
e.g. draw a diagram, make a list, use equations
•
To make a calculated guess,
e.g. guess and check, look for patterns, make suppositions
•
To go through the process,
e.g. act it out, work backwards, before-after
•
To change the problem,
e.g. restate the problem, simplify the problem, solve part of the problem\"

[Champion]

CoffeeCat:

Hi, model drawings is a method that can be used to solve many problems for Singapore's PSLE Maths. However if large numbers are involved \"better methods\" (but based on the same principle) are used sometimes. So yes, it's probably a must for moving to upper primary maths (but some may argue otherwise :scared: )
Math Heuristics are essentially a set of techniques used to solve questions. I believe there is a thin assessment book called Problem-Solving with Heuristics.
Model Drawing can be seen as a heuristic too.
Quoted from moe maths syllabus
\"Thinking skills and heuristics
Students should use various thinking skills and heuristics to help them solve mathematical problems. Thinking skills are skills that can be used in a thinking process, such as classifying, comparing, sequencing, analysing parts and wholes, identifying patterns and relationships, induction, deduction and spatial visualisation. Some examples of heuristics are listed below and grouped in four categories according to how they are used:
•
To give a representation,
e.g. draw a diagram, make a list, use equations
•
To make a calculated guess,
e.g. guess and check, look for patterns, make suppositions
•
To go through the process,
e.g. act it out, work backwards, before-after
•
To change the problem,
e.g. restate the problem, simplify the problem, solve part of the problem\"

Hi coffeecat,
Thanks so much for the clarification; understands better now :hi5:

Guess I have to read up / to do this coming June holiday lioa :imcool: