Q&A - P5 Math

[iCreative Math]

sembgal:

iCreative Math:

Alternative Method - (some students may find it easier to understand with a simple \"box\" model):


You can draw a box picture (which I can't here) to show as follows:-

Cost of 1 Apple = 1 unit
Cost of 1 Pear = 1 unit + $ 0.70

Cost of 42 Apples = 42 units
Cost of 12 Pears = 12 units + 12 x $ 0.70 = 12 units + $ 8.40

put the two box models, one on top of the other, and the student will see clearly

30 units = $ 8.40
1 unit = $ 0.28
42 units = $ 11.76

Mrs Tan spent $ 11.76 on the apples.

Best Regards,
iCreative Math

This method is easy to understand. Are you a tutor from iCreative Math?

Yes I am. I started iCreative Math. I am glad you found the method easy to understand.

Regards.

[711mum]

Appreciate it if someone could help with this qns:


Thomas can buy either 36 identical pens or 24 identical markers with the money he has. After buying 8 such markers and 12 such pens, how many more such pens can Thomas buy with the remaining money he has?

TIA

[MathIzzzFun]

711mum:

Appreciate it if someone could help with this qns:


Thomas can buy either 36 identical pens or 24 identical markers with the money he has. After buying 8 such markers and 12 such pens, how many more such pens can Thomas buy with the remaining money he has?

TIA

cost of 24 markers = cost of 36 pens
cost of 8 markers = cost of 12 pens

cost of (8 markers + 12 pens)
= cost of (12 pens + 12 pens)
= cost of 24 pens

36-24=12

Thomas can buy 12 more pens with remaining money.

cheers.

[711mum]

MathIzzzFun:

711mum:

Appreciate it if someone could help with this qns:


Thomas can buy either 36 identical pens or 24 identical markers with the money he has. After buying 8 such markers and 12 such pens, how many more such pens can Thomas buy with the remaining money he has?

TIA

cost of 24 markers = cost of 36 pens
cost of 8 markers = cost of 12 pens

cost of (8 markers + 12 pens)
= cost of (12 pens + 12 pens)
= cost of 24 pens

36-24=12

Thomas can buy 12 more pens with remaining money.

cheers.

Thanks MathIzzzFun for the prompt reply.

Apologies, typo error it should be \"after buying 8 such markers and 15 such pens\", not 12.

I posted the qns as the answer is 9 in the answer key with the following working which I :? :

12+15=27 :scratchhead:
36-27=9

Now I got it, thanks again.

[carol73]

hi


anna had just received her salary on monday. she spent $480 on utility bills and 1/3 of the remainder on a handbag on the second day. after giving $200 to her parents on the third day. she had only a quarter of her salary left. how much was her salary?

[jieheng]

carol73:

hi


anna had just received her salary on monday. she spent $480 on utility bills and 1/3 of the remainder on a handbag on the second day. after giving $200 to her parents on the third day. she had only a quarter of her salary left. how much was her salary?

Salary

[-----480------][--1p--][------2p------]
[-----480------][--1p--][200][---1u---]
[--------------3u-------------][---1u---]

From the models ,

2p = 200 + 1u

480 + 1p + 200 = 3u
1p + 680 = 3u
2 * ( 1p + 680 ) = 2 * 3u
2p + 1360 = 6u
200 + 1u + 1360 = 6u
5u = 1560
1u = 312

Salary --> 4u = 4 * 312 = 1248

[iCreative Math]

carol73:

hi


anna had just received her salary on monday. she spent $480 on utility bills and 1/3 of the remainder on a handbag on the second day. after giving $200 to her parents on the third day. she had only a quarter of her salary left. how much was her salary?

For such questions, we always start from the last info given and work backwards from the last info to the first info given in the question.

Let the total salary be 8 units.

1/4 of the salary left ==> 2 units

gave her parents $ 200 ==> (2 units + 200)

we are told this is 2/3 of the remainder, hence 1/3 of salary spent on handbag is (1 unit + 100)

anna spent $ 480 on utilities ...

============================================

hence the full model is as follows:-

<-- $ 480 --><-- 1 unit + 100 --><-- 200 --><-- 2 units -->

<--------------- total of 6 units -------------><-- 2 units -->

6 units = $ 480 + 1 unit + $ 100 + $ 200

5 units = $ 780

1 unit = $ 156

8 units = $ 1,248

Anna's salary is $ 1,248.


Regards,

iCreative Math



Note: The first few explanatory statements are to help students understand the thinking behind the model. In examinations, only the steps below the ===== are required.

[MathIzzzFun]

carol73:

hi


anna had just received her salary on monday. she spent $480 on utility bills and 1/3 of the remainder on a handbag on the second day. after giving $200 to her parents on the third day. she had only a quarter of her salary left. how much was her salary?

using fractions..

2/3 of Remainder = 2/8 of Salary + $200
1/3 of Remainder = 1/8 of Salary + $100
3/3 Remainder --> 3/8 of Salary + $300

8/8 of salary = Remainder + $480 = 3/8 of Salary + $300 + $480
5/8 of Salary --> $780
Salary --> $780x 8/5 = $1 248

cheers.

[Man_at_work]

iCreative Math:

Your question is incomplete. It is missing one statement that usually says in total they have how many marbles or Bala has 10 more marbles than Amos, etc.

The problem-solving approach will then be as follows:

The ratios between them are 1:2, 1:4, and 2:3, i.e. total of 3 units, 5 units and 5 units respectively.

The lowest common multiple, LCM (which P5 should have learnt) for 3, 5 and 5 is 15.

We therefore start with a total of 15 units for A, B, C & D.

Amos' share compared to the rest is 1:2, hence Amos has 5 units (1/3 x 15).

Chris' share compared to the rest is 1:4,hence Chris has 3 units (1/5 x 15)

Bala's share compared to the rest is 2:3, hence Bala has 6 units (2/5 X 15)

Hence, Darren has 1 unit (15 - 5 - 3 - 6)

In practice, P5 students are not expected to be able to write these statements. These are not necessary. I have included them here to explain the steps. In practice, students need to simply draw a table and complete the table with the number of units A, B, C and D with simple calculation e.g. 1/3 X 15, 2/5 X 15, etc to show how they arrive at the number of units for each person.

Hope this this helpful.

Regards,

iCreative Math

Thanks a lot

[Man_at_work]

MathIzzzFun:

question is incomplete.. here's the approach to obtain the each's share of the marbles :

Amos's marbles --> 1/3 of total number -- Amos -> 1part, Bala+Chris+Darren-> 2parts, total -> 3 parts

Chris's marbles --> 1/5 of total number
Bala's marbles --> 2/5 of total number

1-1/3 -1/5-2/5 = 1/15

Darren's marbles --> 1/15 of total number

I believe you can work from here ..

cheers.

Thanks