daca ai acelasi numitor, aduni ( sau scazi ), dupa caz, numaratorii intre ei.
24/31 + 18/31 = ( 24 + 18 ) / 31 = 42/31
45/19 + 24/19 = 45 + 24/19 = 69/19
15/37 + 18/37 = 15 + 18 / 37 = 33/37
41/11 + 16/11 = 41 + 16/11 = 57/11
29/5 + 42/5 = 29 + 42/5 = 71/5
48/20 + 19/20 = 48 + 19/20 = 67/20
7/28 + 34/28 = 7 + 34/28 = 41/28
/ = inseamna linia de fracție.