Finding area of triangle - puzzled

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Finding area of triangle - puzzled

Postby Lynn2010 » Sun Apr 10, 2016 10:31 am

A friend's son (primary school) recently told me that - to find area of triangle:

1/2 x base x height (i agree)

and his school teacher said:
b x h
2

cannot be used. MOE does not allow.

I'm puzzled. Can someone explain why the (b x h) / 2 is not allowed? Thanks!

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Re: Finding area of triangle - puzzled

Postby Lynn2010 » Sun Apr 10, 2016 8:31 pm

Anyone??

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Re: Finding area of triangle - puzzled

Postby slmkhoo » Mon Apr 11, 2016 8:47 am

Probably it's because they require the student to spell out the formula in the full form? But of course it's the same in terms of results. It's probably a "primary school teacher" issue.

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Re: Finding area of triangle - puzzled

Postby Lynn2010 » Mon Apr 11, 2016 10:16 am

Hmmm.... simkhoo, thanks for the response. I think so.
Maybe the MOE show in the text book as 1/2 x base x height and the teachers just follow. So, yes, in theroy, the teacher is correct - MOE way because they dont see other variations

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Re: Finding area of triangle - puzzled

Postby jetsetter » Mon Apr 11, 2016 12:14 pm

Lynn2010 wrote:Hmmm.... simkhoo, thanks for the response. I think so.
Maybe the MOE show in the text book as 1/2 x base x height and the teachers just follow. So, yes, in theroy, the teacher is correct - MOE way because they dont see other variations



the short cut presentation is allowed in sec school...

Guess in pri school, they are grilling on foundations. Maybe they want slower kids to understand that when they slice the area of a rectangle/square/parallelogram (b x h) exactly into half, you get area of a triangle. Some schools might get them to do origami to understand this basic concept before equilateral, isosceles and scalene triangles appear in their worksheets.

The '1/2' is there to reinforce the concept?? :shrug:

Same reasons why they tell them in 3 X 5, first number 3 refers to the 'group'.

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Re: Finding area of triangle - puzzled

Postby Sun_2010 » Mon Apr 11, 2016 12:26 pm

Lynn2010 wrote:Hmmm.... simkhoo, thanks for the response. I think so.
Maybe the MOE show in the text book as 1/2 x base x height and the teachers just follow. So, yes, in theroy, the teacher is correct - MOE way because they dont see other variations


DS's teacher allows it, most of the times he doesnt even write the formula :stupid: just calculates it.

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Re: Finding area of triangle - puzzled

Postby pirate » Mon Apr 11, 2016 12:30 pm

jetsetter wrote:
Lynn2010 wrote:Hmmm.... simkhoo, thanks for the response. I think so.
Maybe the MOE show in the text book as 1/2 x base x height and the teachers just follow. So, yes, in theroy, the teacher is correct - MOE way because they dont see other variations



the short cut presentation is allowed in sec school...

Guess in pri school, they are grilling on foundations. Maybe they want slower kids to understand that when they slice the area of a rectangle/square/parallelogram (b x h) exactly into half, you get area of a triangle. Some schools might get them to do origami to understand this basic concept before equilateral, isosceles and scalene triangles appear in their worksheets.

The '1/2' is there to reinforce the concept?? :shrug:

Same reasons why they tell them in 3 X 5, first number 3 refers to the 'group'.

Maybe to help the kids to understand the concept, have to explain why half a cake is somehow not equal to the cake divided by 2. :wink: :siam:

Of course, if one applies Occam's Razor, the conclusion will be that the particular teacher was wrong. That's all.

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Re: Finding area of triangle - puzzled

Postby slmkhoo » Mon Apr 11, 2016 12:42 pm

Lynn2010 wrote:Hmmm.... simkhoo, thanks for the response. I think so.
Maybe the MOE show in the text book as 1/2 x base x height and the teachers just follow. So, yes, in theroy, the teacher is correct - MOE way because they dont see other variations

It may also be that it's a new concept that this child's class has just been taught? Teachers are often stricter initially to make sure the kids really know the forumula, then ease off as the year progresses, or as they go to the next level.

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