What rational number is between -2/626 and -1/616 ?

2 Answers
Nov 21, 2017

There are infinitely many, but the one midway between -2/626 and -1/616 is -1/414

Explanation:

Note that -1/616 and -2/626 are rational numbers, with -2/6 < -1/626<16.

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 = -1/412((16)+(26))=(112)+(212)=312=14

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)26 and -(1)/(6)16, 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)26=412

-(1)/(6) = - (2)/(12)16=212

Now you can see that -(3)/(12)312 lies right between them

larr ...... -(4)/(12)412 ........ -(3)/(12)312 .......... - (2)/(12)212 ........ rarr.

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

Example:
Find three fractions between (1)/(5)15 and (2)/(5)25

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)210 .......... (3)/(10)310 .......... (4)/(10)410 .... 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)15=525

(2)/(5) = (10)/(25)25=1025

Now you can easily see four fractions lying between (1)/(5)15 and (2)/(5)25

(1)/(5) = (5)/(25)15=525

(6)/(25)625

(7)/(25)725

(8)/(25)825

(9)/(25)925

(2)/(5) = (10)/(25)25=1025