60-27 = 60 - 20 - 7 = 40 - 7 = 3360-7 = 60 - 7 = 5367-20 = 67 - 20 = 4783-50 = 83 - 50 = 3380-53 = 80 - 50 - 3 = 30 - 3 = 2780-3 = 80 - 3 = 77(80-20)-9 = 60 - 9 = 51100-(4+36) = 100 - 40 = 6090-(53-50) = 90 - 3 = 87
60-27 = 60 - 20 - 7 = 40 - 7 = 33
60-7 = 60 - 7 = 53
67-20 = 67 - 20 = 47
83-50 = 83 - 50 = 33
80-53 = 80 - 50 - 3 = 30 - 3 = 27
80-3 = 80 - 3 = 77
(80-20)-9 = 60 - 9 = 51
100-(4+36) = 100 - 40 = 60
90-(53-50) = 90 - 3 = 87