HARD SUBTRACTION. Be able to answer this in less than one minute.

1.92 20 =   26.84 20 =
2.98 74 =   27.48 34 =
3.73 35 =   28.66 18 =
4.61 37 =   29.63 32 =
5.68 25 =   30.86 38 =
6.84 80 =   31.73 33 =
7.94 43 =   32.88 15 =
8.68 16 =   33.69 13 =
9.73 58 =   34.68 54 =
10.65 39 =   35.88 15 =
11.73 18 =   36.51 12 =
12.79 61 =   37.80 27 =
13.72 68 =   38.63 27 =
14.96 67 =   39.86 55 =
15.57 20 =   40.92 85 =
16.45 41 =   41.97 79 =
17.83 60 =   42.34 29 =
18.56 22 =   43.85 42 =
19.73 36 =   44.90 39 =
20.53 21 =   45.55 34 =
21.33 30 =   46.98 95 =
22.51 28 =   47.61 50 =
23.87 14 =   48.51 47 =
24.80 68 =   49.43 42 =
25.77 37 =   50.86 48 =