What rational number is between #-2/6# and #-1/6# ?

2 Answers
Nov 21, 2017

There are infinitely many, but the one midway between #-2/6# and #-1/6# is #-1/4#

Explanation:

Note that #-1/6# and #-2/6# are rational numbers, with #-2/6 < -1/6#.

Like any two distinct real numbers, there are infinitely many rational numbers between them.

Since they are both rational, their average is also a rational number.

We can arrive at the average by adding the two numbers then halving the result.

So:

#1/2((-1/6)+(-2/6)) = (-1/12)+(-2/12) = -3/12 = -1/4#

Nov 25, 2017

When two fractions are too close to have another one in between, just re-write them with larger denominators to spread them apart enough to fit other fractions in.

Explanation:

It looks like there is no room between #-(2)/(6)# and #-(1)/(6)#, but you can stretch them apart to get more room by writing the same fractions, only this time using the common denominator of 12.

#-(2)/(6) = -(4)/(12)#

#-(1)/(6) = - (2)/(12)#

Now you can see that #-(3)/(12)# lies right between them

#larr# ...... #-(4)/(12)# ........ #-(3)/(12)# .......... #- (2)/(12)# ........ #rarr#.

If you need even more room, just use an even larger denominator.

Example:
Find three fractions between #(1)/(5)# and #(2)/(5)#

Using tenths as the denominator doesn't open up enough room for 3 fractions to fit between them. Only one fraction (3/10) fits.

#larr#...... #(2)/(10)# .......... #(3)/(10)# .......... #(4)/(10)# .... #rarr#

But don't give up if that happens.
Just try again with a bigger denominator.

This time, try 25ths as the denominator.

#(1)/(5) = (5)/(25)#

#(2)/(5) = (10)/(25)#

Now you can easily see four fractions lying between #(1)/(5)# and #(2)/(5)#

#(1)/(5) = (5)/(25)#

#(6)/(25)#

#(7)/(25)#

#(8)/(25)#

# (9)/(25)#

#(2)/(5) = (10)/(25)#