Q&A - P3 Math

[PiggyLalala]

After understanding the solution posted by Ksi and MathIzzzFun, I think Ksi is right: the key in this question is that all 3 cans of paint must be used for the wall.


Perhaps the question can be rephrased to
To paint a complete wall, we need exactly one tin of Paint A, one tin of paint B and one tin of paint C. If only Paint A is used, we are short of 7litres. If only Paint B is used, we are short of 5 litres. If only Paint C is used, we are short of 3 litres. How many litres of paint is required to paint a complete wall? Would this be better?

[PiggyLalala]

After rephrased the question, I discussed the question with my P3 child again. I told him that to paint the wall, we need exactly a tin of Paint A, a tin of paint B and one tin of paint C, that is

A + B + C = Wall

Next, I guide him to tell me what information can we deduce from the statement 'If only Paint A is used, we are short of 7litres.'
He told me B + C = 7
Similarly from the next two statements, we know that A + C = 5
and A + B = 3.

Then I reminded him that we have managed to reduce the question to a similar question that he has done before in P1 and P2:
* + @ = 10
* +* - @ = 2.
What is * and @?

Back to the 'Paint question', my son then told me that
2A + 2B + 2C = 5 + 3 + 7 = 15
therefore A + B + C = 15/2 = 7.5

That is the wall needs 7.5 litres of paint.
This is an alternative approach from me and my son after understanding the question with the help of Ksi and MathIzzzFun. What about yours?

Maths is FUN because it can be done by a few approaches. :lol:

[PiggyLalala]

Another approach ..


http://www.flickr.com/photos/62167097@N02/5804257287/in/photostream

http://i56.tinypic.com/2n1gyuw.jpg\">

cheers.[/quote]

Really like your approach to this question. Never thought that the question be done using model. Cool. From the first bar, we know that
B + C = 7. Then it is back to the usual P1 and P2 model.

B: XXXXXXXX<-----2litres--->
XXXXXXXXXXXXXXXXXXXX
Therefore 2 units = 7 -2 = 5
1 unit = 5/2 = 2.5
B: 2.5

Back to MathIzzzFun model: Therefore the wall: 5 + 2.5 = 7.5 litres.
I really like this approach.

[MathIzzzFun]

PiggyLalala:

PiggyLalala:

After rephrased the question, I discussed the question with my P3 child again. I told him that to paint the wall, we need exactly a tin of Paint A, a tin of paint B and one tin of paint C, that is
A + B + C = Wall

Next, I guide him to tell me what information can we deduce from the statement 'If only Paint A is used, we are short of 7litres.'
He told me B + C = 7
Similarly from the next two statements, we know that A + C = 5
and A + B = 3.

Then I reminded him that we have managed to reduce the question to a similar question that he has done before in P1 and P2:
* + @ = 10
* +* - @ = 2.
What is * and @?

Back to the 'Paint question', my son then told me that
2A + 2B + 2C = 5 + 3 + 7 = 15
therefore A + B + C = 15/2 = 7.5

That is the wall needs 7.5 litres of paint.
This is an alternative approach from me and my son after understanding the question with the help of Ksi and MathIzzzFun. What about yours?

Maths is FUN because it can be done by a few approaches. :lol:

Hi

Math is fun indeed. But many children will inevitably be intimidated by seemingly tough questions and find it boring zzz ... I hope to share different approaches to problem solving and hopefully this will make it from zzz to fun - which is why I use the moniker mathizzzfun

back to the same problem, after you reach
B+C = 7
A+C = 5
A+B = 3

we are back to the typical \"shapes\" type of question

cheers.

[MathIzzzFun]

PiggyLalala:

PiggyLalala:

Another approach ..

http://www.flickr.com/photos/62167097@N02/5804257287/in/photostream

http://i56.tinypic.com/2n1gyuw.jpg\">

cheers.

Really like your approach to this question. Never thought that the question be done using model. Cool. From the first bar, we know that
B + C = 7. Then it is back to the usual P1 and P2 model.

B: XXXXXXXX<-----2litres--->
XXXXXXXXXXXXXXXXXXXX
Therefore 2 units = 7 -2 = 5
1 unit = 5/2 = 2.5
B: 2.5

Back to MathIzzzFun model: Therefore the wall: 5 + 2.5 = 7.5 litres.
I really like this approach.

avec plaisir :lol:

cheers.

[mama_10]

Janet & Rebecca saved a total of $387.6, Janet & Jennifer saved a total of $276.85. If Rebecca and Jennifer saved a total of $200.95, how much did Janet save?

[PiggyLalala]

mama_10:

Janet & Rebecca saved a total of $387.6, Janet & Jennifer saved a total of $276.85. If Rebecca and Jennifer saved a total of $200.95, how much did Janet save?

Janet + Rebecca = 387.6
Janet + Jennifer = 276.85
Rebecca + Jennifer = 200.95

Therefore 2janet + 2rebecca +2jennifer = 865.40
Janet + rebecca + jennifer = 865.40/2 = 432.70

therefore rebecca = 432.70 - 200.95 = 231.75

[teh_oh]

PiggyLalala:

mama_10:

Janet & Rebecca saved a total of $387.6, Janet & Jennifer saved a total of $276.85. If Rebecca and Jennifer saved a total of $200.95, how much did Janet save?

Janet + Rebecca = 387.6
Janet + Jennifer = 276.85
Rebecca + Jennifer = 200.95

Therefore 2janet + 2rebecca +2jennifer = 865.40
Janet + rebecca + jennifer = 865.40/2 = 432.70

therefore rebecca = 432.70 - 200.95 = 231.75

Hi,
Is this P3 or P4 math? Thanks.

[cimman]

teh_oh:

PiggyLalala:

[quote=\"mama_10\"]Janet & Rebecca saved a total of $387.6, Janet & Jennifer saved a total of $276.85. If Rebecca and Jennifer saved a total of $200.95, how much did Janet save?

Janet + Rebecca = 387.6
Janet + Jennifer = 276.85
Rebecca + Jennifer = 200.95

Therefore 2janet + 2rebecca +2jennifer = 865.40
Janet + rebecca + jennifer = 865.40/2 = 432.70

therefore rebecca = 432.70 - 200.95 = 231.75

Hi,
Is this P3 or P4 math? Thanks.[/quote]well, Decimals isn't taught in P4 yet, till the later part of the year.

This looks like algebra to me. It will be interesting to see if modelling can solve this.

[corneyAmber]

http://i54.tinypic.com/2gvog1u.jpg\">