Q&A - P3 Math

[cimman]

this is the LCM (lowest common multiple) method. There will always be a number of matching common multiples. Always pick the lowest one, unless the question qualifies the range, ie. 50 to 60.

[cimman]

tianzhu:

cwc:

Hi Tianzhu,
Very curious, what do you use to produce all these fantastic diagrams/pics to explain?
Impressive :salute: How much time do you need to typically come up with one?

Hi cwc

Good Morning.

I am happy you liked my “masak masak” way of doing maths.

Just like any solutions in this forum, you’re correct to say that efforts are put in to post them.

I am a simple daddy, so I am not very conversant with IT. At times I need to play around with the software which I used in my solutions, which is PowerPoint in this case.

The usual process starts with coming up with some thoughts on the mathematical solutions to the questions. The thoughts are then translated into usually pictorial presentation which I hope will help students see that Maths is beautiful.

Best wishes

you should check out Microsoft Visio. It's a lot easier drawing the stuff you draw in Visio then in Powerpoint, and it's a lot faster as well.

[tianzhu]

Thein:

Tina had some money. If she buys4 erasers she has $1 left. If she buys 8 erasers with the same amount of money she needs $3 more. How much money does Tina have and what is the cost of one eraser?

Hi

I think it’s less efficient to use MM(Multiples method) to solve this question.

You may apply the concept of Gap and Difference.

Gap ------- 1 + 3 ------ 4
Difference in number of erasers -------- 8 - 4 ------- 4

Cost of 1 eraser ------- 4/4 ------- 1
Amount of money -------- 4 + 1 ------- 5

Best wishes

[tianzhu]

Champion:

Hi Tianzhu,
Thank you so much for your clear explanation; got it lioa! :celebrate:

Hi Champion

You're welcome.

Best wishes

[tianzhu]

teh_oh:

Tianzhu and MathIzzFun,

:thankyou: for clarifying

Hi

You're welcome.

Best wishes

[tianzhu]

cimman:

you should check out Microsoft Visio. It's a lot easier drawing the stuff you draw in Visio then in Powerpoint, and it's a lot faster as well.

Hi

I am not familiar with Visio.

Would you like to show us how it would help by posting some of the solutions using it?

Best wishes

[Champion]

Sorry need to trouble all Maths experts here again! Going thru the revision with DD1, realize that I am so weak in Maths especially drawing models, that unable to really help her much .


Q1) Mr. Goh had $125 and Mr. Tan had $80. After each of them paid for a bus ticket to KL, Mr. Goh had 6 times as much money left as Mr. Tan. How much did the bus ticket cost?


Q2) The sum of three numbers is 78. The first number is 7 more than the second number. The third number is 4 less than the second number. Find all the three numbers.

Q3) There are some hens and cows on a farm. These animals have a total of 18 heads and 56 legs. How many cows and how many hens are there on the farm?

:thankyou: :thankyou:

[Thein]

cimman:

this is the LCM (lowest common multiple) method. There will always be a number of matching common multiples. Always pick the lowest one, unless the question qualifies the range, ie. 50 to 60.

Hi cimman
Thank you.

for this problem..does it work?

Mother has some money to buy beef. She will have $15 left if she buys 3kg of beef. However, she will need $3 more if she wants to buy 4kg of beef instead. How much money does Mother have?

sorry to trouble....

Thank you once again.

Hi Tianzhu
i could understand the model. but how to differentiate the problems by reading them.
awaiting for your answer.

Thank you MathIzzFun...not able to get you

[tianzhu]

Thein:

Hi Tianzhu


I need a help.

First, I should thank you for I was able to understand model drawing only with your explanations. Thanks a lot.

i've taught my child, model drawing to solve problems like :
Mrs. Tay has a bag of sweets. If she gives each child 7 sweets, she will be left with 5 sweets. If she gives each child 9 sweets, she will need 5 more sweets.
a) How many children are there?
b) How many sweets are there?

but for this problem:

Mrs. Raju bought a sack of rice which weighed less than 50kg. If she packed the rice into bags of 5kg each, she would have 3kg of rice left. If she packed it into bags of 7kg each, she would have 4kg of rice left. How many kg of rice did Mrs. Raju buy?

i couldn't draw the model.

i've to go for another heuristic approach. finding the multiples....

i don't know how to differentiate the problems...or is there any common method that i can teach my kid...

Thank you in advance.

Hi

First thing first, I’ve to begin by saying that I am not a trained educator, I am a daddy.

So I can only share with you some of my experiences I’ve had in my kid’s PSLE journey. They are entirely my own and may not be always correct.

The common method used by primary students to solve the questions on Mrs Tay and Mrs Raju is “Systematic Listing”. Students usually present their solutions in tabulated list with “Multiples Method’ or MM. This method may be tedious, but is good for less mathematically inclined students. As long as students are careful in their calculations, three or four marks are safe in their bags.

Well, we are in Singapore, where “cheaper, faster and better” is a way of life. That’s why life is stressful.

We are always looking for faster and better method.

You’ll realise that Mrs Tay question can be solved more efficiently using “Gap and Difference” concept.Some may call it \"Excess and Shortage\"

You’ll also realise that the same concept cannot be applied to the Mrs Raju question.

Why?

In Mrs Tay question, the number of children and number of sweets is a fixed number. While in Mrs Raju question, the number of bags is different in the two cases or scenarios.

In GD type of questions, the question usually asks students to find out the number of children/boxes as a part of the question.

In Raju types of questions, usually one is given a range of numbers and asked to find a number within the ranges or is asked to find the lowest possible number.

Observe the two questions and note the differences.

Best wishes

[Thein]

Hi Tianzhu


Thank you so much for all your efforts.
:salute: