P3 Math - Help

[Carndablues]

Putting it in words, if grandpa gave 2 more stamps to each of his grandchildren, that would leave him with 14 stamps less (9 - (-5)). That gives 14/2 = 7 grandkids. The second part is simple, just work backward.

 

This is how I worked it out, but I fear this would only give you 1 mark as it's "quasi" algebra.

 

Can any enlightened beings say how many marks you would get for giving this answer?

[Joseph22]

Actually its not that the school work now is tough. But that we have too many information on match liao. We have a lot of other formula that at times we forget that the answer can be done by a simple matters which might take up a bit of time.

[Geboz]

My version.

 

Is this the method taught to P3 students ?

 

Yes my son has mastered his multiplcation and division, but I seriously doubt he can come up with something like this. Seem like its beyonds his standard (and mine too !). The solution by Sg2303 is easier to understand.

 

 

[Gturismo]

Is this the method taught to P3 students ?

 

Yes my son has mastered his multiplcation and division, but I seriously doubt he can come up with something like this. Seem like its beyonds his standard (and mine too !). The solution by Sg2303 is easier to understand.

 

Sg2303's solution is correct. Guess and check is correct method for this question. I find it is much easier to work out this way:

 

(6 stamps X No. of Grandchildren) + 5 = (8 stamps X No. of Grandchildren) - 9

 

6G + 5 = 8G - 9

 

8G - 6G = 5 + 9

 

2G = 14

 

Hence No. of Grandchildren = 14/2 = 7

 

[Arowana1]

decided to satisfy myself on wat is the expected working so i ask a p3 kid. so happen my son is p3 :-)

 

he read the question, paused for a second or two, and wrote down 7.

 

when i ask him for working, he said no working. so i asked him how he gets his answer. he said, if give 2 more stamps each results in having to incur 14 stamps total, so must be 7 grandchildren cos 2*7=14 or the other way round is 14/2 is 7.

 

said he will juz write 7. dats all. wat else is there to show...

 

so there i was, with my algebra and everything, instead he solved is using wat i tink is rational thinking? no need formula etc. juz some common knowledge. now dats wat we should expect from p3! not those chim big table of guess or algebra.

 

is my son rite? i really dunno cos his teachers did write in the comm book dat he always write answer only, never show working hahaha when i reprimand him previous times, he always quote me the scene from "day after tomolo".

 

oh well....

[Geboz]

I have been staring at you post trying to figure out how you son arrived at the the magical number 7, but I can't.

 

 

 

 

[Ah_cow]

yes.. no need algebra and bar model.

 

6 stamps each left 5

8 stamps each short 9

 

give 2 more stamps to:

1st grandchild left 3

2nd gchild left 1

3rd.... short 1

.

.

6th grandchild short 7

7th grandchild short 9

[Moozzie]

Ok, let me try again.

 

Imagine You have 5 dollars left. You want to give all your grandchild 2 dollars extra but that 5 dollars isn't enough; you will need 7 dollars more.

 

So in order to give your grandchildren 2 dollars more, you will need a total of $14 (5+7). That means you have 7 grandchildren (14/2).

But....how we know we need 7 dollars more? We don't how many grandchildren in the first place?

 

Sori ah... my math weak. But the table model is clear and understandable.

[Unltd]

Please help to solve this P3 math using methods known to a P3 student, no algebra allowed.

 

This is too tough for me

 

Question:

Grandpa has some stamps.

If he gives 6 stamps to each of his grandchildren, he will have 5 stamps left over.

If he gives 8 stamps to each of his grandchildren, he will be short of 9 stamps.

 

a) How many grandchildren does Grandpa have ?

 

b) How many stamps fors Grandpa have ?

 

I know I know its a trick question . Stamps are physical items, cannot be negative items to give away! haahahaha

[Rayoh]

if granpa has got 20 grandchildren??? How??

Table method all the way???.... Its going to be tedious.

 

Bro Kusje method

Key point is you need good understanding of problem sum...

[Carndablues]

yes.. no need algebra and bar model.

 

6 stamps each left 5

8 stamps each short 9

 

give 2 more stamps to:

1st grandchild left 3

2nd gchild left 1

3rd.... short 1

.

.

6th grandchild short 7

7th grandchild short 9

 

Thank you for your contribution, you have the win.

 

[Carndablues]

I have been staring at you post trying to figure out how you son arrived at the the magical number 7, but I can't.

 

This is genuine advice.

 

Can you do your kids a favour and send them to a tutor?

 

This isn't hard.

[Carndablues]

I believe they use guess and check method for this question.

 

Ain't it known as "trial-and-error" or have they Singaporeanised that word too?

[KoseiWish]

Been scrolling through this topic I thought that only me got this problem with my son's P3 maths .. others too ..education wise so much different nowadays..

 

[Tohto]

Ask my daugther at P3 to do this question. Below was how she solved it.

 

If grandpa has 7 grandchildren,

7 x 6 = 42

8 x 7 = 56

56 - 9 = 47

47 - 5 = 42

a) He has 7 grandchildren

b) He has 47 stamps.

[Kusje]

This is how I worked it out, but I fear this would only give you 1 mark as it's "quasi" algebra.

 

Can any enlightened beings say how many marks you would get for giving this answer?

 

If you get the correct answer at the end with any legit method, you will get full marks.

[Kusje]

But....how we know we need 7 dollars more? We don't how many grandchildren in the first place?

 

Sori ah... my math weak. But the table model is clear and understandable.

 

Sorry. Typed wrongly. I meant 9 dollars more.

 

"If he gives 8 stamps to each of his grandchildren, he will be short of 9 stamps."

[Ah_cow]

haha how she get the if grandpa has 7 grandchildren?