Son's teacher needs to go back to school

DVardysShadow

meritaten wrote: »

All I can think is that I THOUGHT I Knew what < and > meant! now, can you mathematical geniuses please clarify whether:
+ means addition
- means subtraction
* or X means multiplication
and / or (the symbol missing from the keyboard ie a dash with a dot above and below) means division.

I am now totally confused!!!!!!!!!!!!!!!!!!!!!!!

Yes they do mean what you think, but they are only mere operators [which undertake transformations].

All the real fun is with relationships such as < and > and even =, which relate numbers to each other and to the results of operations between numbers. These are a real barrel of laughs as we are discovering on this thread. They have the added feature of being relational operators in computing - ie like + , - * and / they can also return results [although this is limited to TRUE and FALSE]. The resulting confusion is adding to the entertainment.

A tip: this is all heading towards propositional and even predicate calculus - that should give you an hour's headstart.

welshgirl78

Ok, my final attempt to explain what I meant!

In the statement y > x, yes y is greater than x but it is equally correct to say x is less than y, yet the symbol is the one traditionally written as greater than.

Therefore, > 30 can be (incorrectly) thought of as less than 30

I know it is wrong, I know it should be 30 is less than something. I don't think I ever said I thought the statement was right (although I will check back as I am sure many others will) I was merely trying to explain or consider WHERE the misconception came from.

Personally I don't necessarily consider the symbol to mean greater than as it is an equally correct statement to read it in either direction. I think it is oversimplifying to say it must be greater than, in maths you can read it correctly in either direction. However I can see it is wrong to say it is traditionally read as less than, I apologise, it was late and I was irritated. It can be read either way, although is not a statement unless there is something either side of the symbol.

Finally, no smoke screens intended. I had literally just finished 2 core 3 papers, as you know teachers love to work. Plus this is a misconception, google it, there are loads and I (honestly) thought it might be interesting after this query generated 5 pages of discussion.

My first proper MSE argument

DVardysShadow

bestpud wrote: »

You've still not answered how > can mean <.

(4>3) <=> (3<4)

should do the trick.

Meepster

DVardysShadow wrote: »

A tip: this is all heading towards propositional and even predicate calculus - that should give you an hour's headstart.

mmmm - formal systems...yummy

Sambucus_Nigra

redpete wrote: »

You are allowed to think that, people are allowed to think the Sun orbits the Earth, or that the moon is made of cheese, or that "would of" means the same as "would've" but these are not correct either.

you < hilarious.

See; it's only relevant if something is on one or other side.

Tigsteroonie

welshgirl78 wrote: »

In the statement y > x, yes y is greater than x but it is equally correct to say x is less than y, yet the symbol is the one traditionally written as greater than.

Therefore, > 30 can be (incorrectly) thought of as less than 30

I know it is wrong, I know it should be 30 is less than something.

Precisely!!!! It is wrong.

y > x
if you read from left to right (normal): y is greater than x
if you read from right to left: x is less than y

> 30
if you read from left to right: whatever you have is greater than 30
if you read from right to left: 30 is less than whatever you have.

How anybody can read that incorrectly (unless they have dyscalculia) is beyond me.

Meepster

welshgirl78 wrote: »

Ok, my final attempt to explain what I meant!

In the statement y > x, yes y is greater than x but it is equally correct to say x is less than y, yet the symbol is the one traditionally written as greater than.

Therefore, > 30 can be (incorrectly) thought of as less than 30

I know it is wrong, I know it should be 30 is less than something. I don't think I ever said I thought the statement was right (although I will check back as I am sure many others will) I was merely trying to explain or consider WHERE the misconception came from.

Personally I don't necessarily consider the symbol to mean greater than as it is an equally correct statement to read it in either direction. I think it is oversimplifying to say it must be greater than, in maths you can read it correctly in either direction. However I can see it is wrong to say it is traditionally read as less than, I apologise, it was late and I was irritated. It can be read either way, although is not a statement unless there is something either side of the symbol.

Finally, no smoke screens intended. I had literally just finished 2 core 3 papers, as you know teachers love to work. Plus this is a misconception, google it, there are loads and I (honestly) thought it might be interesting after this query generated 5 pages of discussion.

My first proper MSE argument

Re: The highlighted quote:

No, no, no, no, no...something is greater than 30, NOT 30 is less than something!!!

DVardysShadow

Tigsteroonie wrote: »

....

> 30
if you read from left to right: whatever you have is greater than 30
if you read from right to left: 30 is less than whatever you have.

How anybody can read that incorrectly (unless they have dyscalculia) is beyond me.

"Whatever you have" is purely implied in that expression. It has no symbol. So the first miracle is that anyone can read it correctly and the second miracle is that there is a correct interpretation for something meaningless.

DVardysShadow

Sambucus_Nigra wrote: »

you < hilarious.

Is meaningless because you and hilarious are not members of the same ordered set.

Poppy9

welshgirl78 wrote: »

Ok, my final attempt to explain what I meant!

In the statement y > x, yes y is greater than x but it is equally correct to say x is less than y, yet the symbol is the one traditionally written as greater than.

Therefore, > 30 can be (incorrectly) thought of as less than 30

I know it is wrong,

Not being funny but you KNOW IT IS WRONG but you still try to say it's right!! I'm confused!!