Son's teacher needs to go back to school

Humphrey10

Meepster wrote: »

> always means greater than in the same way that < always means less than. But is determined by where they number is.

The trouble is, if you tell people "> always means greater than", and then give them this expression:
30>x
and ask them
is x greater than 30?
then some people will say 'yes, it's greater than 30, there is a greater than symbol there'.
Some people really are that innumerate.

I still think it is easier to forget the names,
x > y is the same as y < x , x is bigger than y, you don't need to know which symbol is which, just which end of the symbol is which eg which end the smaller number goes on.

Meepster

Humphrey10 wrote: »

The trouble is, if you tell people "> always means greater than", and then give them this expression:
30>x
and ask them
is x greater than 30?
then some people will say 'yes, it's greater than 30, there is a greater than symbol there'.
Some people really are that innumerate.

I still think it is easier to forget the names,
x > y is the same as y < x , x is bigger than y, you don't need to know which symbol is which, just which end of the symbol is which eg which end the smaller number goes on.

So you're saying if we teach them wrong, they'll learn better?

Meepster

Sambucus_Nigra wrote: »

There's no need to be quite so rude.

Not everyone in the world was taught maths reading from the left to the right.

For me, I see '>' meaning that the thing on the left is greater than the thing on the right.

> on it's own is meaningless until something is on either side.

With all due respect, I am allowed to see that, as this is how I see things.

Of course, you can see things however you want. You are welcome to believe that grass is blue, but it doesn't mean you are right...

> ISN'T meaningless, it means "is greater than" whether on it's own or accompanied by letters and/or numbers. That is a FACT and not open to interpretation...

onlyroz

Humphrey10 wrote: »

The trouble is, if you tell people "> always means greater than", and then give them this expression:
30>x
and ask them
is x greater than 30?
then some people will say 'yes, it's greater than 30, there is a greater than symbol there'.
Some people really are that innumerate.

Technically, before you can infer anything about x you have to "solve the expression for x", i.e. get x on the left hand side of the expression. So:
30 > x
solving for x:
x < 30
Therefore, x is less than 30.
Although I know in this example it should be obvious to most people.

onlyroz

Sambucus_Nigra wrote: »

> on it's own is meaningless until something is on either side.

That's like saying "+" is meaningless unless there's something either side.
Or "a" is meaningless unless it's part of a word.
">" is a mathematical operator with a well established meaning of "greater than".

Humphrey10

Meepster wrote: »

So you're saying if we teach them wrong, they'll learn better?

Where did I say teach them something that is wrong? I just said don't get hung up on the names.

Meepster

Humphrey10 wrote: »

Where did I say teach them something that is wrong? I just said don't get hung up on the names.

But not "getting hung" on the name IS teaching them wrongly.

It has a name for a reason, it explains its purpose, teaching anything else would be rather silly...

daska

Humphrey10 wrote: »

Where did I say teach them something that is wrong? I just said don't get hung up on the names.

You're quite right, you didn't say anything about teaching them, you said "tell". And that's quite a difference, telling someone something doesn't imply that you ensure they understand it.

Humphrey10

Meepster wrote: »

But not "getting hung" on the name IS teaching them wrongly.

It has a name for a reason, it explains its purpose, teaching anything else would be rather silly...

I mean, don't just teach people what it is called, also of more importance is how it works.
You can't just say ' > is a greater than symbol ' then expect people to work out that x > y is equivalent to y < x, that 30>x doesn't mean x is greater than 30 despite the only symbol being a greater than symbol.
It might be obvious to you, but it is not obvious to many people, especially primary school children.

daska

Humphrey10 wrote: »

I mean, don't just teach people what it is called, also of more importance is how it works.
You can't just say ' > is a greater than symbol ' then expect people to work out that x > y is equivalent to y < x, that 30>x doesn't mean x is greater than 30 despite the only symbol being a greater than symbol.
It might be obvious to you, but it is not obvious to many people, especially primary school children.

Which is why the emphasis in teaching is on understanding, not just facts.