Need Help in Primary 6 Maths Qns

[Koko]

For a primary 6 question, it should not be using algebra to solve.... they not yet started on this subject. right?

[Xdeatel]

Sowwieee. i type wrong ;( is 28.

 

 

 

Devi is 28, Ken is 60. FINAL ANSWER!

Edited March 11, 2010 by Xdeatel

[Wbucket]

Ya, primary 6 using simultaneous equation, is it considered high level? Sometimes also don't know how we can solve the problem with primary 6 math knowledge.

[Sg2303]

This is the answer for P6 level.

 

[Sg2303]

This may be better for explaning:

 

Edited March 11, 2010 by Sg2303

[Ben5266]

[bigcry] [bigcry] I can't solve this!!! [bigcry]

[Xdeatel]

This may be better for explaning:

 

This should be the best explanation.

 

And im surprised p6 question getting tougher !

[Requiemdk]

I need some help on the following Maths Qns which I have trouble explaining to my kid. Anyone kind enough to guide me with the explanation?

 

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

I'm of the opinion that if you want your kid to have an easier time in secondary school, quit playing around with the model method (which they WILL have to unlearn eventually) and teach algebra ASAP. IIRC the teachers now are not allowed to mark algebraic solutions incorrect.

 

The model method and algebraic solution is already posted here.

 

Try this next one, which relies on interpreting the data in a different way and using simple logic. It's essentially the same method without all the fanciful diagrams and arcane algebraic notation (well, arcane to a P6 kid who hasn't touched it yet). Maths should be simple and logical. :)

 

If Devi had 16 bucks more, she'd have the same amount as Ken minus 16. So Ken has 32 bucks more than Devi. If Devi gives 20 bucks to Ken, Ken would then have 72 bucks (remember giving 20 away means she's short of 20 and Ken has another 20) more than Devi which is 10 times of what Devi would then have. So Devi has 8 bucks after giving Ken 20. So she originally has 28 bucks, and Ken originally has 60 bucks.

Edited March 11, 2010 by Requiemdk

[Wadexu]

You need to use the total unchange concept. Detail attached.

[Xdeatel]

You need to use the total unchange concept. Detail attached.

 

wtf?

 

HOW COME SO COMPLICATED

[Lengendcf]

Last time when we learnt Algebra was during secondary school.

 

Primary, no need to learn Algebra.

 

Don't know which farking idiot invented the "model problem solving" and let the primary school students learn???

 

That idiot think drawing should be easy for the kids.

 

But nothing can compare to the power of Algebra, you think the kids grow up will draw models to solve questions?

 

Why can't just let the children enjoy their primary school days happily?

 

IDIOT!!

 

[Mivec9]

You need to use the total unchange concept. Detail attached.

 

agree, for primary school, they need to use box method.

 

If ken gives $16, he will have same amt as Devi ->

 

Step 1. So Ken has $32 more

 

Step 2. if Devi gives Ken $20, amt she has will be 1/10 of Ken's.

Deduct $20 from Devi and put at Ken's box.

 

 

Step 3. Now, Ken has 1 Unit + $20 + $32 + $20

Devi now has 1 Unit

 

Step 4. Since Devi's 1 Unit = 1/10 of Ken's

Hence, 9Unit = $20 + $32 + $20

9Units = $72

1 Unit = 72/9 = $8

 

Step 5. Amt Ken has = 1 Unit + 32 + 20

= 8 + 52 = 60 (ans)

 

[Kxbc]

Even if I have PhD which I don't have btw, I still need to solve using algebra. Lucky I don't have kids to coach.

[Wind30]

I need some help on the following Maths Qns which I have trouble explaining to my kid. Anyone kind enough to guide me with the explanation?

 

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

 

very simple.

 

explain to your kid.

 

if ken gives devi $16, he will have the same amount of money as Devi. What does this mean?? It means ken has $32 more than Devi. Because ken -$16 devi +$16.

 

So when devi gives ken $20, ken will have $36+$40=$72 more.

 

From here, you no need simulataneous equation.

Let x be devi's money after she gives $20.

10*x=x+72 one equation, one variable.

x=8. Even no algebra, trail and error also can find the answer.

 

So ken has $60.

 

 

As I said so many times, primary school maths GOT learn algebra with one unknown. But NEVER learn simultaneous equation (ie with 2 or more unknowns).

 

[Lengendcf]

So means the model cannot be solved without algebra?

 

Still have 1 unknown must use algebra to solve?

 

Using just algebra is.. your left ear is itchy, just lift up your right hand, bring towards your face and reach the left ear to scratch it hard and you will feel song..

 

Using model is like same left ear is itchy, also use right hand, but this time bring behind your head and can only lightly scratch the left ear. Not very song.

[Yapahfai]

I need some help on the following Maths Qns which I have trouble explaining to my kid. Anyone kind enough to guide me with the explanation?

 

"If Ken gives Devi $16, he will have the same amount of money as Devi. If Devi gives Ken $20, the amount she has will be 1/10 that of Ken's. How much money does Ken have?"

 

from first sentence, Ken has $32 more than Devi.

 

from second sentence, now Ken has $72 more than Devi.

Ken=10 units, Devi=1 unit

 

Difference= 9 units= $72

1 unit=$72/9=$8.

10 units=$10x8=$80

 

Ken has $80.

[Wbucket]

I'm of the opinion that if you want your kid to have an easier time in secondary school, quit playing around with the model method (which they WILL have to unlearn eventually) and teach algebra ASAP. IIRC the teachers now are not allowed to mark algebraic solutions incorrect.

 

The model method and algebraic solution is already posted here.

 

Try this next one, which relies on interpreting the data in a different way and using simple logic. It's essentially the same method without all the fanciful diagrams and arcane algebraic notation (well, arcane to a P6 kid who hasn't touched it yet). Maths should be simple and logical. :)

 

If Devi had 16 bucks more, she'd have the same amount as Ken minus 16. So Ken has 32 bucks more than Devi. If Devi gives 20 bucks to Ken, Ken would then have 72 bucks (remember giving 20 away means she's short of 20 and Ken has another 20) more than Devi which is 10 times of what Devi would then have. So Devi has 8 bucks after giving Ken 20. So she originally has 28 bucks, and Ken originally has 60 bucks.

Are you a primary school teacher? Asking because teaching isn't as easy as what everyone thought. And it is common that having 1-2 kids understand doesn't mean you can get the whole class to do the same. My GF and I, each has strenght n weakness, and we constantly remind ourselves what is obvious to 1, might be totally alien to the other. She told me not far back that when she is young, she totally can't understand algebra.

 

Personally think the graphical method is clearer than words.

Edited March 12, 2010 by Wbucket

[Requiemdk]

Are you a primary school teacher? Asking because teaching isn't as easy as what everyone thought. And it is common that having 1-2 kids understand doesn't mean you can get the whole class to do the same. My GF and I, each has strenght n weakness, and we constantly remind ourselves what is obvious to 1, might be totally alien to the other. She told me not far back that when she is young, she totally can't understand algebra.

 

Personally think the graphical method is clearer than words.

 

Close. Yes, teaching isn't as easy as people think it is, but dumbing everything down to pretty pictures and "models" is doing the kid a disservice for many reasons. The "model" method may be clearer than words to you, but the kid cannot rely on it forever. Learning is hard work and the function of a teacher is not to dumb everything down to pretty pictures and graphs but to guide and explain difficult concepts and techniques so that the learner understands.

 

Teaching something abstract such as algebra and logic in particular takes a massive amount of patience and expertise. A lot of kids run into grief when they first encounter algebra because 1. they have to unlearn the silly model method and 2. it's usually the first time they have to WORK REALLY HARD at comprehending something, which is made even more difficult when they're suddenly taking twice the number of subjects and each subject is suddenly so much more demanding. You really need a teacher who can go beyond gimmicky toys to "concretize" abstract stuff and reciting textbook material to do the job properly.

 

Graphs are usually preferred simply because people are more used to interpreting information from pictures rather than taking the time to follow an argument. Best to teach the kid to get into the habit of thinking at an early age.