List and describe the steps you would use to model 7/10 - 4/10.

We have
7/10 - 4/10

1) fractions that have a common denominator
Combine the numerators together, put the  difference over the common denominator 
(7-4)/10=3/10
2) reduce to lowest terms if possible
3/10=0.30

the answer is 0.30