Check this site.
http://library.thinkquest.org/J002328F/impmix.htm
How do you make a mixed number into a improper fraction?
2 answers
Ex: 1 2/3
Numerator = 1x3+2=5
Keep Denominator
Answer: 5/3
Numerator = 1x3+2=5
Keep Denominator
Answer: 5/3