Arithmetic Operator Puzzles

#3937: 8 _ 6 _ 3 _ 7 = 11 medium #3938: 8 _ 6 _ 3 _ 8 = 12 medium #3939: 8 _ 6 _ 3 _ 8 = -4 medium #3940: 8 _ 6 _ 3 _ 9 = 13 hard #3941: 8 _ 6 _ 3 _ 9 = -5 medium #3942: 8 _ 6 _ 3 _ 9 = 4 easy #3943: 8 _ 6 _ 4 _ 8 = 11 medium #3944: 8 _ 6 _ 4 _ 2 = 11 medium #3945: 8 _ 6 _ 4 _ 6 = 17 hard #3946: 8 _ 6 _ 4 _ 8 = 5 easy #3947: 8 _ 6 _ 4 _ 2 = 5 easy #3948: 8 _ 6 _ 4 _ 6 = -1 easy #3949: 8 _ 6 _ 4 _ 8 = -4 medium #3950: 8 _ 6 _ 4 _ 1 = 13 hard #3951: 8 _ 6 _ 4 _ 2 = 14 hard #3952: 8 _ 6 _ 4 _ 3 = 4 easy #3953: 8 _ 6 _ 4 _ 4 = 16 hard #3954: 8 _ 6 _ 4 _ 4 = 8 medium #3955: 8 _ 6 _ 4 _ 5 = 17 hard #3956: 8 _ 6 _ 4 _ 5 = 7 easy #3957: 8 _ 6 _ 4 _ 6 = 18 hard #3958: 8 _ 6 _ 4 _ 6 = 6 easy #3959: 8 _ 6 _ 4 _ 7 = 19 hard #3960: 8 _ 6 _ 4 _ 8 = 4 easy #3961: 8 _ 6 _ 5 _ 3 = 18 hard #3962: 8 _ 6 _ 5 _ 2 = -7 medium #3963: 8 _ 6 _ 5 _ 3 = -2 easy #3964: 8 _ 6 _ 5 _ 3 = 20 hard #3965: 8 _ 6 _ 6 _ 4 = 17 hard #3966: 8 _ 6 _ 6 _ 9 = 12 hard #3967: 8 _ 6 _ 6 _ 4 = -1 easy #3968: 8 _ 6 _ 6 _ 9 = 4 easy #3969: 8 _ 6 _ 7 _ 3 = -6 medium #3970: 8 _ 6 _ 8 _ 4 = 20 hard #3971: 8 _ 6 _ 8 _ 4 = 11 medium #3972: 8 _ 6 _ 8 _ 3 = -8 medium #3973: 8 _ 6 _ 8 _ 4 = -4 medium #3974: 8 _ 6 _ 8 _ 4 = 5 easy #3975: 8 _ 6 _ 8 _ 2 = 3 easy #3976: 8 _ 6 _ 8 _ 3 = 18 hard #3977: 8 _ 6 _ 8 _ 3 = 2 easy #3978: 8 _ 6 _ 9 _ 3 = 10 medium #3979: 8 _ 6 _ 9 _ 6 = 12 hard #3980: 8 _ 6 _ 9 _ 3 = 6 medium #3981: 8 _ 6 _ 9 _ 6 = 4 easy #3982: 8 _ 6 _ 9 _ 3 = 16 hard #3983: 8 _ 6 _ 9 _ 1 = 13 hard #3984: 8 _ 6 _ 9 _ 2 = 14 hard