Medium Arithmetic Puzzles

#384: 1 _ 8 _ 3 _ 2 = 12 medium #388: 1 _ 8 _ 4 _ 5 = 11 medium #393: 1 _ 8 _ 4 _ 3 = -5 medium #400: 1 _ 8 _ 4 _ 6 = 8 medium #401: 1 _ 8 _ 4 _ 6 = -4 medium #402: 1 _ 8 _ 4 _ 6 = 12 medium #403: 1 _ 8 _ 4 _ 7 = 9 medium #404: 1 _ 8 _ 4 _ 7 = -5 medium #405: 1 _ 8 _ 4 _ 7 = 14 medium #406: 1 _ 8 _ 4 _ 8 = 10 medium #407: 1 _ 8 _ 4 _ 8 = -6 medium #413: 1 _ 8 _ 5 _ 4 = 11 medium #420: 1 _ 8 _ 6 _ 2 = 11 medium #421: 1 _ 8 _ 6 _ 3 = 10 medium #424: 1 _ 8 _ 6 _ 4 = 12 medium #427: 1 _ 8 _ 7 _ 4 = 14 medium #429: 1 _ 8 _ 8 _ 2 = 12 medium #430: 1 _ 8 _ 8 _ 4 = 10 medium #436: 1 _ 8 _ 9 _ 9 = 7 medium #438: 1 _ 9 _ 2 _ 3 = 7 medium #440: 1 _ 9 _ 2 _ 3 = -5 medium #441: 1 _ 9 _ 2 _ 2 = 8 medium #444: 1 _ 9 _ 3 _ 2 = 7 medium #447: 1 _ 9 _ 3 _ 2 = -5 medium #448: 1 _ 9 _ 3 _ 3 = 8 medium #451: 1 _ 9 _ 3 _ 3 = 6 medium #452: 1 _ 9 _ 3 _ 4 = 7 medium #453: 1 _ 9 _ 3 _ 4 = 12 medium #454: 1 _ 9 _ 3 _ 5 = -2 medium #456: 1 _ 9 _ 3 _ 6 = 9 medium #457: 1 _ 9 _ 3 _ 6 = -3 medium #458: 1 _ 9 _ 3 _ 7 = 10 medium #460: 1 _ 9 _ 3 _ 8 = -5 medium #462: 1 _ 9 _ 3 _ 9 = -6 medium #467: 1 _ 9 _ 4 _ 6 = -5 medium #468: 1 _ 9 _ 4 _ 3 = 12 medium #472: 1 _ 9 _ 5 _ 5 = 8 medium #475: 1 _ 9 _ 6 _ 4 = -5 medium #478: 1 _ 9 _ 6 _ 6 = 8 medium #482: 1 _ 9 _ 7 _ 7 = 8 medium #488: 1 _ 9 _ 8 _ 4 = 7 medium #491: 1 _ 9 _ 9 _ 3 = 6 medium #492: 1 _ 9 _ 9 _ 9 = 8 medium #501: 2 _ 2 _ 2 _ 6 = 13 medium #508: 2 _ 2 _ 3 _ 9 = 8 medium #509: 2 _ 2 _ 3 _ 9 = -4 medium #513: 2 _ 2 _ 3 _ 5 = 16 medium #531: 2 _ 2 _ 4 _ 7 = -6 medium