# Struggling with maths need a little help

• Sep 2nd 2008, 01:55 AM
$ilver Struggling with maths need a little help I am strugling with some basic maths and I wonderd if someone would explain this to me, I think I am looking at it all wrong. 4-(-3)=7 correct? Well I dont understand this. If I had 4 marbles and used the (-3) on them I would be left with 1 marble right? Sorry guys if this seems realy dumb but I find it realy hard to get my brain around maths (Crying)$ilver
• Sep 2nd 2008, 02:03 AM
Simplicity
Quote:

Originally Posted by $ilver I am strugling with some basic maths and I wonderd if someone would explain this to me, I think I am looking at it all wrong. 4-(-3)=7 correct? Yes, this is correct. Mathematically, we can apply this. Quote: Originally Posted by$ilver
Well I dont understand this.

If I had 4 marbles and used the (-3) on them I would be left with 1 marble right?

Sorry guys if this seems realy dumb but I find it realy hard to get my brain around maths (Crying)

$ilver For the marble question, you cannot have $-3$ marbles so that question (I believe) is asking what whould happen if there were $4$ marbles and you take $3$ away. $4\text{ marbles} + (-3\text{ marbles}) = 1\text{ marbles}$ For objects, you cannot have a number less than $0$ so when given, you assume that they are saying, what happens when this quantity is subtracted. • Sep 2nd 2008, 02:17 AM$ilver
Quote:

For the marble question, you cannot have -3 marbles so that question (I believe) is asking what whould happen if there were 4 marbles and you take 3 away.

$4\text{ marbles} + (-3\text{ marbles}) = 1\text{ marbles}$

For objects, you cannot have a number less than 0 so when given, you assume that they are saying, what happens when this quantity is subtracted.
So basicaly then I am thinking of numbers as objects? Like when I count on my fingers each finger is an object of the number it represents?

Why isnt 4-(-3)=7 written 4+3=7 ? and what happens to the - in (-3)? it isnt reflected in the answer that I can see.

OMG im realy confused now!! (Rofl)
• Sep 2nd 2008, 02:29 AM
Simplicity
Quote:

Originally Posted by $ilver So basicaly then I am thinking of numbers as objects? Like when I count on my fingers each finger is an object of the number it represents? Why isnt 4-(-3)=7 written 4+3=7 ? and what happens to the - in (-3)? it isnt reflected in the answer that I can see. OMG im realy confused now!! (Rofl) $4 - (-3) = 4 + 3 = 7$ When you have two signs together, like above then there is a change of sign. $x- (-y) = x + y$ $x + (-y) = x - y$ $x - (+y) = x-y$ $x + (+y) = x + y$ Like signs make positive and different signs make negative. • Sep 2nd 2008, 02:29 AM ban26ana Quote: Originally Posted by$ilver
So basicaly then I am thinking of numbers as objects? Like when I count on my fingers each finger is an object of the number it represents?

Why isnt 4-(-3)=7 written 4+3=7 ? and what happens to the - in (-3)? it isnt reflected in the answer that I can see.

OMG im realy confused now!! (Rofl)

I can't think of numbers as objects. They're just numbers, I guess.

Whenever you multiply a negative number by a negative number, the answer is positive. This is essentially what you are doing here. You are multiplying the number -3 by -1. Although the 1 isn't written, it is assumed. So yes, it could be written as 4 + 3 = 7. It's the same thing. But then that would be too easy. LOL
• Sep 2nd 2008, 02:44 AM
$ilver Ok gotcha! I didnt understand how the signs worked, that helps a lot guys. Thanks (Rock) PS would you beleive im 39?!! I wanted to do a science course on open university but I have discoverd my maths is SO BAD in need to learn it before I even start the course!! • Sep 2nd 2008, 02:55 AM$ilver
Quote:

Originally Posted by Air
$4 - (-3) = 4 + 3 = 7$

When you have two signs together, like above then there is a change of sign.

$x- (-y) = x + y$
$x + (-y) = x - y$
$x - (+y) = x-y$
$x + (+y) = x + y$

Like signs make positive and different signs make negative.

Ummm where do the multiply signs fit into all this? (Thinking)
• Sep 2nd 2008, 03:03 AM
Simplicity
Quote:

Originally Posted by $ilver Ummm where do the multiply signs fit into all this? (Thinking) I'm not sure what you mean by multiplication sign. The rules that I have given are arithmetic addition and subtraction rule. Have a read on this websites, it explains rules of addition, subtraction, multiplication and division: Link (Arithmetic Rules) • Sep 2nd 2008, 03:23 AM$ilver
Just what I needed (Rofl)
• Sep 2nd 2008, 06:17 PM
saranya
Quote:

Originally Posted by $ilver I am strugling with some basic maths and I wonderd if someone would explain this to me, I think I am looking at it all wrong. 4-(-3)=7 correct? Well I dont understand this. If I had 4 marbles and used the (-3) on them I would be left with 1 marble right? Sorry guys if this seems realy dumb but I find it realy hard to get my brain around maths (Crying)$ilver

u have mentioned in a bracket know that is 4-(-3) that means multiplication so 4 (- * - in the bracket )3 is equal as 4 + 3 = 7
when u just say 4-3 means that is 1 only
In multiplication when the signs r same + symbol
when opposite sign means - symbol
now u may understood i think