Q&A - PSLE Math

[shurley197323]

Thanks Tianzhu. Please explain kindly explain why 9 units ?

What is the reason behind to separate into parts & units ?
Sorry if I sound silly.

[tianzhu]

shurley197323:

Thanks Tianzhu. Please explain kindly explain why 9 units ?

What is the reason behind to separate into parts & units ?

Hi shurley197323

Good Morning.

I tried to rush out the solution in text form last night because of “SOS”.
Units and Parts is used to differentiate the fractions of Wendy and Pei Fen. As seen from the MD, they are of different units of measurement.

Hope this helps.

Best wishes

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[shurley197323]

Hi.Tianzhu. Very very much appreciated. Thanks for all the trouble.

[anneshirleygilbert]

Hello Tianzhu,


It’s many days since you posted the answer to the question on Circles A, B and C. Didn’t have time to go through it until now. The presentation is so beautiful… and your steps so methodically laid out. Just want to say thanks.

Sincerely,
Anne

[tianzhu]

Hi shurley197323


I’ll take it that calculators can be used for your questions.
For Q1, you may use MD or work in tabulated form using Number* Value Method.

As for Q2, I did a quick check, the answer is 179 marbles. I’ll post the solution at a later time if there is no solution coming from other members.

Hope this helps.

Best wishes

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[tianzhu]

shurley197323:

Hi.Tianzhu. Very very much appreciated. Thanks for all the trouble.

Hi shurley197323

You're welcome.

Best wishes

[tianzhu]

anneshirleygilbert:

Hello Tianzhu,


It's many days since you posted the answer to the question on Circles A, B and C. Didn't have time to go through it until now. The presentation is so beautiful... and your steps so methodically laid out. Just want to say thanks.

Sincerely,
Anne

Hi anneshirleygilbert

You're welcome.

Best wishes

[peggy]

please help with this !


A bag consisting of $ 2 & $ 10 notes has a total value of $648. 7 pcs of $10 were exchanged for $2 notes of similar value. In the end, the number of notes was the same as the $ 2 notes. How many $ 2 were there at first ?

many thanks…

[tianzhu]

peggy:

A bag consisting of $ 2 & $ 10 notes has a total value of $648. 7 pcs of $10 were exchanged for $2 notes of similar value. In the end, the number of notes was the same as the $ 2 notes. How many $ 2 were there at first ?

Hi peggy

Perhaps, some information is missing, please check your source.

I think “In the end, the number of notes was the same as the $ 2 notes. “ should be read as “In the end, the number of $10 notes was the same as the $ 2 notes. “

A quick one

I’ll take it as a P6 question and will work using ratios.

The key to unlock this question is to recognise that the total amount of money remains the same before and after.

7 pieces of $ 10 notes ---------- $70 ----------- changed into 35 pieces of $2 notes

The end ratios for the number of notes for $2 and $10 are 1:1.

Using Number* Value Method, work out the number of notes in the end.

2units: 10 units
12 units ------ 648

1 unit ------ 54

Number of $2 notes -----54

Number of $2 notes at first ----- 54 – 35 -----19

Best wishes

[peggy]

Tianshu,


You’re right ! I have missed out some info. And you are right - In the end, the number of $ 10 notes are the same as the $ 2 notes.

Btw, this is a P5 question and my son has not learnt ratio…
Any beautiful models to show ?? Hope is not too much to ask for. I always enjoy reading your answers with your beautifully illustrated models.

Thanks in advance.