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

1.26 13 =   26.58 27 =
2.89 89 =   27.84 33 =
3.68 29 =   28.42 11 =
4.91 45 =   29.60 14 =
5.77 77 =   30.71 71 =
6.72 21 =   31.31 10 =
7.87 26 =   32.44 34 =
8.60 46 =   33.98 16 =
9.68 40 =   34.74 44 =
10.74 15 =   35.69 26 =
11.92 51 =   36.98 65 =
12.79 49 =   37.81 12 =
13.53 37 =   38.58 18 =
14.72 57 =   39.61 46 =
15.76 68 =   40.82 78 =
16.96 65 =   41.56 54 =
17.66 17 =   42.84 74 =
18.86 43 =   43.70 61 =
19.93 93 =   44.47 17 =
20.52 42 =   45.97 82 =
21.98 26 =   46.93 27 =
22.44 22 =   47.73 40 =
23.74 21 =   48.82 26 =
24.96 61 =   49.97 72 =
25.88 61 =   50.94 60 =