In order to write the decimal 8.5 in fraction form, or any decimal as a fraction, we need to first get it to a whole number over a whole number. In this case if we consider 8.5 to be 8.5/1 we can multiple both the numerator and the denominator by 100:
100/100 * 8.5/1
This gives 85/10.
Next we find the lowest common factor for the numerator and denominator as shown in the video. That means that 8.5 can be expressed as the fraction 85/10. This can be reduced further to 17/2.
When we express decimals or numbers as fractions we need to make sure we have both the numerator and denominator are in their simplest form. We can do this by dividing both by a common factor.
This general technique can be used to find the fraction for any decimal number. Note that for something like 0.256 you would only multiple by 1000/1000. For 0.88 you would multiply by 100/100.
