3/10=0.3 2,3+(1,5-0,7)= 2.3 + 0.8 = 3,1
3/4=0.75 6,75-(2,35+0,23)=6.75 - 2.58 = 4,17
2/5=0.4 3,4-(0,9+0,45)=3.4 - 1.35 = 2.05
12/25=0.48 (12.4 - 9.35) + 2.48 = 3.05 + 2.48 = 5.53
1/20=0.05 (27.61-8.11) + 4.05= 19.5 + 4.05 = 23.55
9/10=0.9 (6.35-2.05)+0.9=4.3+0.9 = 5.2