What is #7 9/10# as an improper fraction?
Remember that a whole number is:
In this case we are working with the fraction 'tenths'.
Each whole number is
In 7 whole numbers there will be
There are also 9 extra 'tenths'.
In total there are
With practice you would start to use shortcuts and speed up solving this type of question.
Multiply by 1 and you do not change the value. But 1 comes in many forms so you can change the way a number looks without changing its value.