this is because i added up 1/2 and 3/4 first, which gave me 1 1/4, and i converted this into just a single fraction without a whole number to make the adding easier for me which was 5/4.
(a whole number is the amount of times the bottom number of the fraction went into the top number so-... 4 goes into 5 one time which gives you a whole number of 1 and the fraction of 1/4. the 1 being left from the five.)
then i added 5/4 and 7/16 to get 1 11/16. which then converted into 27/16
