+0

# Dividing fractions

+1
365
1

Why is (2/10)/(-1/5)=-1 and not 0? 2/10=0.2 and -1/5=-0.2, right? I really can't wrap my head around this one..

Oct 3, 2017

#1
+1

Why is (2/10)/(-1/5)=-1 and not 0? 2/10=0.2 and -1/5=-0.2, right? I really can't wrap my head around this one..

I will try to answer you but I may not home in on exactly what your problem is so I would very much like you to respond to what I say :)

1)   First   /  is a fraction line which is the same as divide.

for instance

$$2/3=\frac{2}{3 }=2\div 3$$

2)   next, a positive number divided by a negative number is always negative.

$$\frac{2}{-3 }=2\div -3 = -\frac{2}{3}$$

3) Any number (including fractions and decimals) divided by itself is 1

For example:

5 divided by 5 means how many 5s go into 5 and the answer is obviously 1

4)  When you divide some number by another then you are cutting the first one into peices.

So if you have a non zero number and you divide it by another number then the answer can NEVER be 0.  That would be impossible!     So the answer definitely cannot be 0.

5) I think you have division and subtraction muddled up.  The 2 are totally different things.

2 divided by 2 = 1        whereas         2-2=0

NOW

$$(2/10)/(-1/5)\\=\frac{2}{10}\div \frac{-1}{5}\\=0.2\div -0.2\\=-(0.2\div0.2)\\=-1$$

Think about all the points I have made. This is a conceptual problem you are having and hopefully what I have written will help you sort it out :)

Oct 3, 2017
edited by Melody  Oct 3, 2017

#1
+1

Why is (2/10)/(-1/5)=-1 and not 0? 2/10=0.2 and -1/5=-0.2, right? I really can't wrap my head around this one..

I will try to answer you but I may not home in on exactly what your problem is so I would very much like you to respond to what I say :)

1)   First   /  is a fraction line which is the same as divide.

for instance

$$2/3=\frac{2}{3 }=2\div 3$$

2)   next, a positive number divided by a negative number is always negative.

$$\frac{2}{-3 }=2\div -3 = -\frac{2}{3}$$

3) Any number (including fractions and decimals) divided by itself is 1

For example:

5 divided by 5 means how many 5s go into 5 and the answer is obviously 1

4)  When you divide some number by another then you are cutting the first one into peices.

So if you have a non zero number and you divide it by another number then the answer can NEVER be 0.  That would be impossible!     So the answer definitely cannot be 0.

5) I think you have division and subtraction muddled up.  The 2 are totally different things.

2 divided by 2 = 1        whereas         2-2=0

NOW

$$(2/10)/(-1/5)\\=\frac{2}{10}\div \frac{-1}{5}\\=0.2\div -0.2\\=-(0.2\div0.2)\\=-1$$

Think about all the points I have made. This is a conceptual problem you are having and hopefully what I have written will help you sort it out :)

Melody Oct 3, 2017
edited by Melody  Oct 3, 2017