Do you know what the whole number part is? That's just the number without the decimal portion, right?
What's left, the decimal portion, is the fraction part of the mixed number. So you just need to write that decimal portion as a fraction (easy enough to do, just put it over the appropriate power of 10) and then REDUCE it.
Then you'll have your whole number part, and your fraction part.
I'll do a DIFFERENT number as an example for you. You should then understand how to apply that to your own problem.
Suppose I want to convert 11.84 to a mixed number.
The whole number part is 11.
The fraction part is the piece that is "less than 1", the decimal portion. so I need to convert 0.84 to a fraction.
Remember what 0.84 is: "eighty-four hundredths". That is, 2 decimal places means that it is a portion out of the number 1 followed by TWO zeros, right?
As a fraction then, that is:
\(\dfrac{84}{100}\) and all that I need to do is REDUCE that. So I need to pull out all my common factors:
I see both numbers are even so I can certainly pull out a 2 to get started:
\(\dfrac{84}{100}=\dfrac{2\cdot42}{2\cdot50}\)
Still have two evens so I can pull out another factor of 2:
\(\dfrac{2\cdot42}{2\cdot50}=\dfrac{2\cdot2\cdot21}{2\cdot2\cdot25}=\dfrac{4\cdot21}{4\cdot25}\)
21 and 25 have no more common factors, so that is all I can pull out, now to reduce I just cancel the 4's:
\(\dfrac{\cancel4\cdot21}{\cancel4\cdot25}=\dfrac{21}{25}\)
So my complete answer then, is the whole number part + the fraction part:
\(=11+\dfrac{21}{25}=11\dfrac{21}{25}\)
Now follow the same procedure for 6.35. :)