Tutor MathsGuru: Ask me for your burning Maths questions!

[Guan Hui]

Eh… MMM the answer is 74…

when evelyn gave joyce 38 sweets, the amount of sweet joyce have reduce by 38.
joyce amount of sweet increase by 38.
therefore 150-38-38= 74

Example with smaller terms:
Tom have 3 coins. Harry have 1 coin.
( Tom have 2 more coins than harry)
If Tom give harry 1 coin.
Tom have 2 coins. Harry have 2 coins.
(Tom have 2-1-1=0 more coins than Harry)


Thats why must minus twice… hope it helps MMM

[KSP]

MMM:

Herbie:

Ans is 150-38= 112.

The answer given was 74. 150-38-38.

I am like :?

Let say Evelyn has 150 and Joyce has 0 initially.
After Evelyn gave 38 to Joyce , Evelyn left with 150-38=112
But now Joyce 38.
So Evelyn has 112-38=74 more than Joyce.

[MMM]

Thanks… yes it makes sense now.


I feel that some math question are to test english and not maths…

[mathsguru]

MMM:

I've some questions for P3 and appreciate your help on how to approach the question. Taken this from P3 CH SA1 paper. I want to understand how to teach my P3 to approach such questions in the future as they don't give much information and subjected to interpretation.


43) Evelyn has 150 sweets more than Joyce. If Evelyn gives Joyce 38 sweets, how many more sweets will Evelyn have than Joyce?

THanks.

Hi MMM,

Here's my solution.

It's best to draw out a diagram to visualise it more quickly and easily, because the way the question is phrased can be very misleading at first glance. That's what I advise my P3 students as well.

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=TswuvIi

[mathsguru]

:thankyou: for all your well wishes! *touched*


Keep the questions coming... :D,
MathsGuru

[lemofish]

lovekidsverymuch:

mathsguru:

http://www.postimage.org/image.php?v=TswuvIi

mathsguru the way of ur teaching very nice :celebrate: and makes the sum look very simple

I have a question:

40 children in Class A are having a muffin party. 26 of them eat a vanilla muffin each and 32 of them eat a chocolate muffin each. Everyone in the class eats at least 1 muffin. How many children eat both a vanilla muffin and a chocolate muffin?

[Guan Hui]

26+32=58(no of muffins ate)

58-40=18(If each child ate only 1 muffin there will be extra 18 muffins that was eaten)
Ans: 18 (so 18 of the children ate both vanilla and chocolate)

[Vanilla Cake]

Hi Mathsguru,

Pls help my P5 younger sister to solve this 4-mark question from http://www.orlesson.org/orp/09Ma/2009-Math-SA1-ACS.pdf using models. Thank you.

The volume of water in bottle P was 3/5 of that in bottle Q. After 60 ml of water was added to bottle P and 20 ml was poured away from bottle Q, the amount of water in bottle P was 3/4 that in bottle Q. What was the amount in each bottle at first?

Other than models, what are your recommended method/s to tackle such problem sum?

[lemofish]

Got it! Thank you!

[Guan Hui]

Hi vanilla cake! ,

other ways.. for me the most convenient is of course algebra.

Algebra
P amount = x
Q amount = y
5x=3y-----1
4(x+60)=3(y-20)
4x+240=3y-60
4x+300=3y------2
5x=4x+300
x=300ml
y=500ml

Ratio(sort of)
P :Q
3units :5units
+60 -20
3 units +60= 3nUnits(nunits= new units)
1 nunit= 1unit+20
3 :4 (ratio is in nunit)
3u +60:4u+80

5 u-20=4u+80
1u=100
initially P have 3 u.. so 300ml.
Q have 5 u... so 500ml.


Hope you understand 1 of them=/