# Question

Hi, this Qns is from the P5 textbook under chap 2 whole numbers. Its one of the word problems and need to use model diagram to solve it. I only know how to solve it using substitution method. Can someone enlighten me how to use model diagram for this qns. Thanks in advance.

Source: St Andrew’s Junior

[Kim] + [Mei] ——- [Yanti] + [220]
[Yanti] + [Mei] ——- [Kim] + ]140]
[Kim] + [Yanti] + [Mei] + [Mei] ——- [Kim] + [Yanti] + [220] + [140]
Mei ——- (220 + 140)/2 = 180

Ans : 180 stamps.
Note :
Kim ——- 270
Yanti ——- 230

Hi,

I saw that you use —- lines.

Are they —>    or  =   ?

The teachers in school already have different opinion on the use of —> and = .

And now you are using  —— lines.

In case you are unaware, use ‘arrows’ for ‘percentages and rates’ and ‘equal signs’ for ‘units’ according to MOE. For others, listen and obey teacher-in-charge’s instructions; always. An example is your use of ‘u’ instead of ‘unit”.

It is neither   —>   nor  =.

For my 1u, I just follow the rule of algebraic equation, which students will be learn in Secondary 1.

1u = 10 is the same as 1a = 10 or 1b = 10. This is what pupils are learning in P6.

You may treat my 1u as 1 unit.

But for me, 1u is just an algebraic expression.

Anyway, thanks for your information from MOE.

So far, my pupils change all percentage to algebra,

100% become 100u.

So they have no ambiguous in writing —> and =.

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Hi Sir,

However, you may not expain your —— line symbol in your problem solving.

It is neither —>  nor =.

Please explian just this point. Thank you.

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Hi Sir,
However, you may not expain your —— line symbol in your problem solving. (There is no need to explain as my students will do the necessary.)
It is neither —> nor =. (Yes, it is.)

Please explian just this point. Thank you.  (As above and you are welcome.)

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Hi Sir,

Hi Sir,
Thank you for your no reply. ( I have replied as above and you are welcome.)

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(Please refer to my bracket in brackets.)
It is neither —> nor =. ( Yes)
For my 1u, I just follow the rule of algebraic equation, which students will be learn in Secondary 1.
1u = 10 is the same as 1a = 10 or 1b = 10. This is what pupils are learning in P6. (It is a P5 Math question here and your reply shows that you are ignorant of “The word “unit” should also be fully spelt out, as opposed to only writing the letter “u”..)
You may treat my 1u as 1 unit. (I am aware of this.)

(To be continued…)

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This is a Simultaneous Equation question.

 R1 R2 R1 + R2 Kim 1 -1 0 Yati -1 1 0 Mei 1 1 2 Total 200 140 340

2u  = 340

1u = 340 ÷ 2 = 170 Mei

Checking

200 – 170  = 30 (kim more than Yati)

500 – 30 = 470

470 ÷ 2 = 235  Yati

235 + 30 =  265 Kim

235 + 170 = 405 Mei and Yati

405 – 140 = 265 Kim

This method is not using model diagram to solve it.