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

1.75 42 =   26.45 10 =
2.86 22 =   27.97 14 =
3.35 11 =   28.82 56 =
4.88 10 =   29.88 81 =
5.47 27 =   30.86 70 =
6.83 47 =   31.43 29 =
7.61 34 =   32.92 89 =
8.37 16 =   33.43 19 =
9.61 50 =   34.97 84 =
10.92 71 =   35.67 27 =
11.26 13 =   36.80 18 =
12.98 84 =   37.38 21 =
13.40 10 =   38.71 27 =
14.94 36 =   39.28 11 =
15.43 32 =   40.95 49 =
16.51 41 =   41.76 34 =
17.59 53 =   42.86 72 =
18.79 37 =   43.92 50 =
19.69 39 =   44.82 72 =
20.38 38 =   45.40 10 =
21.81 56 =   46.97 39 =
22.96 45 =   47.88 49 =
23.67 34 =   48.62 44 =
24.69 34 =   49.99 56 =
25.93 89 =   50.96 12 =