Question

What is 6.9 as a fraction or a mixed number

Answer 1

If you're looking for a fraction:
Think of it this way, the 9 is in the 10th place. The 6 is in front of the decimal. So, it's 69/10. The 10 takes the place of the 9, the "/" is the decimal moved to the right one space.

Or 

If you're looking for a mixed number:
You basically split the above fraction "69/10" up into two separate pieces. So, it's
6 9/10.