# Negative or minus

Discussion in 'Mathematics' started by poet, Sep 4, 2011.

1. ### poetNew commenter

Hi all
I have posted this in primary but wondered if anyone could help here too so apologies for double post.
Just a quick query...
I was always of the opinion
that numbers lower than zero were negative numbers ie; -3 would be
negative 3 not minus 3 as minus is an operation.
We have just
bought into a maths scheme in school *shudder* and one of the teaching
points in the first unit I am looking at is that "negative numbers
should be referred to as negative 2, 3, 4 etc. except for when reading
temperature when they should be minus 1, 2, 3, etc."
correct? or not so much?
Cheers! P

2. ### poetNew commenter

Hi all
I have posted this in primary but wondered if anyone could help here too so apologies for double post.
Just a quick query...
I was always of the opinion
that numbers lower than zero were negative numbers ie; -3 would be
negative 3 not minus 3 as minus is an operation.
We have just
bought into a maths scheme in school *shudder* and one of the teaching
points in the first unit I am looking at is that "negative numbers
should be referred to as negative 2, 3, 4 etc. except for when reading
temperature when they should be minus 1, 2, 3, etc."
correct? or not so much?
Cheers! P

3. ### DMNew commenter

Meteorology has its own symbolic language. They actually record negative temperatures as M4 instead of -4 so I think it is clear what they think! They reserve the use of - to mean a small amount of something e.g. -SN is a small snowfall).

4. ### PaulDGOccasional commenter

I believe part of what we should* be explaining to kids is that many things in maths are the result of conventions and history and that sometimes the conventions of other branches of knowledge don't always line up exactly with the conventions we use in maths.

Another example is gradient - our definition of gradient is the tangent of the line with the x axis.

Geographers use the sine.

(Though they tend not to be explicit about it so the difference is often overlooked.)

*Though you don't usually find these things on any Scheme of Work.

5. ### Maths_MikeNew commenter

This is confusing! and has been debated on this forum before if you do a search.
My prefernce when teaching is to say negative when referring to a negative number and then minus is reserved for subtraction.
this helps (me at least) when teaching
if you subtract a neagtive it is the same as adding.
(to minuses make a plus is horrendous and should be banned)
However as others have mnetioned kids need to accept that they will meet various uses of these words and the context of the problem becomes important to undersatnding.

6. ### Maths_MikeNew commenter

I would agree with negative numbers.
temperature well it is common language use to refer to it being minus 5 and you wont hear many people saying the temperature is negative 5 so the kids need to know both.

7. ### pipipi

In numbers I would probably say negative 5
In temperature I would say minus 5
On Axes I would say minus 5.

There are probably other areas where I might mention it. Like the quadratic formula

8. ### poetNew commenter

thank you!
I think i've gotten my head around it and will explain to the children about the varying uses.

9. ### DeborahCarolNew commenter

I am a tutor and have over the years been surprised at the number of children who getto Year Ten and Year Eleven who don't understand the four operations and negative numbers.
However, when they are told that 'two minuses make a plus', and when given an analogy, eg if you don't not have brown hair, you do',the fog lifts - 'oh, that's so easy!'
This 'rule' helps them enormously, especially in algebra.

10. ### DeborahCarolNew commenter

PS Before anyone jumps on me - it's easy for multiplying and dividing. And quite easy for subtracting - they just need to understand that the minuses have to be together, eg -3 - -4. (And when they know this there should be no confusion in addition either.)