Take 2 1/7 - first multiply the denominator by the whole number to give 14 and now add the numerator to this number to get 15 - the fraction in improper form is 15/7. Do the same process with 1 1/4 - so 4 x 1 = 4 and now 4 + 1 = 5 - the new fraction is 5/4.
