Q&A - P3 Math

[Tang]

EN:

Hi Tang


I like your solution on qs 1. It's short and simple and the diagram helps.
I would like to try teaching my kids using your method but I'm a bit lost as to how to explain on certain portion.

I understand the top part but stuck in the following:

2 u --> 89 - 65 = 24

I understand where the 2u come from but how to explain why

89-65 =

TIA

The difference is 2 u.
And the difference between the 2 models is 89 - 65.

[wangsoon]

My son has school homework which I was not able to do without resorting to algebra. Hope you can help.


3 similar apples and 3 similar pears cost $7.50
5 apples and 4 pears cost $11.
What is the cost of 1 apple.

Any ideas?

[Tang]

wangsoon:

My son has school homework which I was not able to do without resorting to algebra. Hope you can help.


3 similar apples and 3 similar pears cost $7.50
5 apples and 4 pears cost $11.
What is the cost of 1 apple.

Any ideas?

7.50 / 3 = 2.50

2.50 x 4 = 10

11 - 10 = $1

The cost of 1 apple is $1.

[wangsoon]

Thanks. So simple. I am overly complicated!

[MoonFlower]

Ya, no algebra in P4. My ds told me a class boy was taught using that to solve but teacher did emailed saying not at this level. I agreed with the other parents, guess and check. Actually, i do feel that the children are using a more simple method just that at our times we were not taught and we don;t see it as what the children learn and see now. Parents got fed up and complaining it’s tough. I simply told my ds, please pay attention to yr teachers if not please approach them for help. School did told us to remind our children on this as I also worry not to confuse my ds.

[watmekiasu]

Tang:

wangsoon:

My son has school homework which I was not able to do without resorting to algebra. Hope you can help.


3 similar apples and 3 similar pears cost $7.50
5 apples and 4 pears cost $11.
What is the cost of 1 apple.

Any ideas?

7.50 / 3 = 2.50

2.50 x 4 = 10

11 - 10 = $1

The cost of 1 apple is $1.

I'm a bit blur here. Doesn't \"3 similar apples and 3 similar pears cost $7.50\" means 6 fruits costing $7.50. Hence, shouldn't it be
7.50 / 6 ?

[Full.010894Cream]

wangsoon:

My son has school homework which I was not able to do without resorting to algebra. Hope you can help.


(1) 3 similar apples and 3 similar pears cost $7.50
(2) 5 apples and 4 pears cost $11.
What is the cost of 1 apple.

Any ideas?

from (1), 12 apples and 12 pears = $7.50 x 4 = $30
from (2), 15 apples and 12 pears = $11 x 3 = $33
therefore, 3 apples = $3 or $1/apple

[Dharma]

wangsoon:

My son has school homework which I was not able to do without resorting to algebra. Hope you can help.


3 similar apples and 3 similar pears cost $7.50
5 apples and 4 pears cost $11.
What is the cost of 1 apple.

Any ideas?

Hope this is helpful

http://www.postimage.org/

[Merlion]

> I agreed with the other parents, guess and check.


I don’t think that this is a guess and check problem. At least, this will not be a good example for using guess and check method. It will be too time consuming to do that.

> Doesn’t "3 similar apples and 3 similar pears cost $7.50" means 6 fruits costing $7.50.

No. It means that the 3 apples are of the same kind (maybe red apple or green apple) and 3 pears are of the same kind (maybe Japanese pear or Australia pear) but apples are not the same as pears.

[watmekiasu]

Tk u Dharma and Merlion, I now understand. :oops: