The average of any two numbers always falls between those two numbers.
So one number between 0.65340 and 0.65345 could be
(0.65340 + 0.65345)/2 = 1.30685/2 = 0.653425
You can also compare the first several digits of the two numbers:
0.65340
0.65345
They both have the same digits up to the 5th digit after the decimal point. So you can get any number between them by incrementing (increasing by 1) the last digit to get e.g. 0.65341, or tack on any number of more digits to get a number larger than 0.65340, like 0.635401 or 0.63540000123, etc.