P2 Math - General Discussion

Academic support for Primary 2
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jedamum
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Post by jedamum » Sat Dec 06, 2008 11:44 am

tamarind wrote: Are maths puzzles supposed to be like this ?
tamarind, this is a form of 'number patterns' questions.
the answer can be derived from 50+30+10=90; 20+40+ ? =90; ? = 90-40-20 = 30.
chamonix wrote:
He only has to write down how he derived it, i.e 51-39 = 50-40+2. Your son is great in Math. Was he attending preschool in US?

The school textbook does teach P1 kids to add/subtract in a way (regrouping) similar to your ds' method, i.e 50 =50+1 but not 39=40-1.

Mine faces the same problem of not showing workings. But, I suppose this issue would be quite common, especially for those kids who do abacus or other Math enrichments...
number bond method of 50-39 is
50* - 39** = (40-30)+(10-9) = 10+1 = 11
*40+10 **30+9

If the syllabus teaches numberbonds subtraction, i think some teacher may not give full marks for using other methods of working like in abacus method regardless if the answer is correct. They may even deduct half a mark if they are so particular.

I think school teachers will deduct marks for not showing workings. I even heard of them deducting marks for not labelling the workings properly (ie not writing down the key words).

ChiefKiasu
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Post by ChiefKiasu » Sat Dec 06, 2008 12:44 pm

tamarind wrote:...The answer is 40 - 10 = 30.

I am not experienced with maths puzzles :oops: I thought the answer is not logical.

Although there are clues :
50 - 20 = 30
50 - 40 = 10

But if we put 30 in that circle, on the other side, 20 - 30 does not give 30.

Are maths puzzles supposed to be like this ?
The answer should be 90-40-20 = 30

The sum of the connected vertices is equal to 90.

The kids will be used to these "puzzles" from P1 onwards.

clare
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Post by clare » Sat Dec 06, 2008 12:51 pm

chamonix wrote: He only has to write down how he derived it, i.e 51-39 = 50-40+2. Your son is great in Math. Was he attending preschool in US?
Hello Chamonix
Yes, my DS attended preschool in the US but only for a year (we started late) before we went back to Singapore for a while. Right now he's in kindergarten in the US. Actually, I can't tell if he's good in math; he's capable of saying he doesn't know what 4+5 is :shock: But once in a while he will surprise me by proclaiming that since 6+6=12, then 8+6 is just 2 more than 6+6 so the answer is 12+2...
He will probably not do well in the Singapore system if schools are so rigid about presenting the right workings... bah!

How do you encourage your child to show the related workings?

clare
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Post by clare » Sat Dec 06, 2008 1:18 pm

tamarind wrote: What is the purpose of identifying those few students who are the cream of the crop ? They are already good enough. They don't need any more help. Principals and teachers should be more concerned about identifying the weakest students and giving them more help.
My dear HOD friend told me that for his school (can't name it here but it's one of the so-called top schools), the teachers set difficult papers with the purpose of identifying the weaker students, so they can give them extra coaching. Er, I wonder if he was just giving me the politically correct answer or it's really true... hmm.

mwchua
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Post by mwchua » Sat Dec 06, 2008 2:19 pm

hi all,

I tried accessing the website www.misskoh.com.sg but could no longer get the website.

Any idea where this webiste has been shifted to ?

Many thanks for your help.

Rgds.
Ming


lantian
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Post by lantian » Sat Dec 06, 2008 3:20 pm

mwchua wrote:hi all,

I tried accessing the website www.misskoh.com.sg but could no longer get the website.

Any idea where this webiste has been shifted to ?

Many thanks for your help.

Rgds.
Ming
Hi
How about trying www.misskoh.com?

metz
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Post by metz » Sat Dec 06, 2008 5:40 pm

clare wrote:
chamonix wrote: He only has to write down how he derived it, i.e 51-39 = 50-40+2. Your son is great in Math. Was he attending preschool in US?
Hello Chamonix
Yes, my DS attended preschool in the US but only for a year (we started late) before we went back to Singapore for a while. Right now he's in kindergarten in the US.
Hi Clare,

I'm rather intrigued by the way US preschools teach Math. I know of a friend whose son is attending the US preschool. The way they teach Math is different. For instance, her 4+ years old was learning 100 by grouping in tens, twenties etc. Think he was also learning addition and subtraction by regrouping too. It's really a good way for kids to explore Math.
Actually, I can't tell if he's good in math; he's capable of saying he doesn't know what 4+5 is :shock: But once in a while he will surprise me by proclaiming that since 6+6=12, then 8+6 is just 2 more than 6+6 so the answer is 12+2...
Same here. My ds would surprise me in a similar way. Now he's into multiplication. Would come up with stuff like 4x50 = two 2x50 = 2x100=200, 5x9=2x9+2x9+1x9=45 (cos he forgot what's 3x9 :roll: ). I have never taught or shown him such methods. Think he simply gets kicks from doing that. Guess our kids just like numbers?
He will probably not do well in the Singapore system if schools are so rigid about presenting the right workings... bah!
Don't worry, kids will adapt fast. At least mine did. We just returned to Sg last year too. :)
How do you encourage your child to show the related workings?
Told my ds that without the workings, the teacher might suspect he didn't know the answers but guessed it, and therefore would consider it as wrong. That worked :wink:

metz
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Post by metz » Sat Dec 06, 2008 6:26 pm

jedamum wrote: If the syllabus teaches numberbonds subtraction, i think some teacher may not give full marks for using other methods of working like in abacus method regardless if the answer is correct. They may even deduct half a mark if they are so particular.

I think school teachers will deduct marks for not showing workings. I even heard of them deducting marks for not labelling the workings properly (ie not writing down the key words).
Yes, that's exactly what some mothers (with kids in primary schools) told me too. Die die, must teach our kids to show workings :P

EN
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Post by EN » Sat Dec 06, 2008 11:27 pm

chamonix wrote
Told my ds that without the workings, the teacher might suspect he didn't know the answers but guessed it, and therefore would consider it as wrong.
That's another way ds loses his marks. It does not help if the papers are set too easy that can simply use mental calculation. Takes a while for him to lose the bad habit.

Clare wrote
My dear HOD friend told me that for his school (can't name it here but it's one of the so-called top schools), the teachers set difficult papers with the purpose of identifying the weaker students, so they can give them extra coaching. Er, I wonder if he was just giving me the politically correct answer or it's really true... hmm.
I think it is more for the opposite. Finding the cream of the crop. To identify weaker students, just take those that score low marks or those who score below average.

ChiefKiasu
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Post by ChiefKiasu » Sat Dec 06, 2008 11:40 pm

EN wrote:chamonix wrote
Told my ds that without the workings, the teacher might suspect he didn't know the answers but guessed it, and therefore would consider it as wrong.
That's another way ds loses his marks. It does not help if the papers are set too easy that can simply use mental calculation. Takes a while for him to lose the bad habit...
On the contrary, my son's school seem to try to impress on the students the need to do mental calculations! They are given tests every other week for "mental sums" where they have to write down the answer without calculation on paper. I've yet to see my son penalized for not showing working in any of his math tests. So I'm wondering if I would be telling him wrong if I insisted that he show all his working for his answers.

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