Medium Arithmetic Puzzles

#532: 2 _ 2 _ 4 _ 8 = 9 medium #533: 2 _ 2 _ 4 _ 8 = -7 medium #534: 2 _ 2 _ 4 _ 9 = 10 medium #537: 2 _ 2 _ 4 _ 4 = 17 medium #539: 2 _ 2 _ 5 _ 3 = 16 medium #544: 2 _ 2 _ 6 _ 2 = 13 medium #550: 2 _ 2 _ 9 _ 3 = 8 medium #552: 2 _ 2 _ 9 _ 3 = -4 medium #562: 2 _ 3 _ 4 _ 8 = 8 medium #564: 2 _ 3 _ 4 _ 8 = -4 medium #565: 2 _ 3 _ 4 _ 8 = 12 medium #577: 2 _ 3 _ 6 _ 7 = -6 medium #578: 2 _ 3 _ 6 _ 8 = 9 medium #579: 2 _ 3 _ 6 _ 8 = -7 medium #580: 2 _ 3 _ 6 _ 9 = 10 medium #588: 2 _ 3 _ 6 _ 7 = 11 medium #590: 2 _ 3 _ 6 _ 8 = -4 medium #592: 2 _ 3 _ 6 _ 9 = -5 medium #595: 2 _ 3 _ 7 _ 3 = 14 medium #598: 2 _ 3 _ 8 _ 4 = -4 medium #600: 2 _ 3 _ 8 _ 2 = 10 medium #604: 2 _ 3 _ 8 _ 4 = 12 medium #606: 2 _ 3 _ 9 _ 9 = 7 medium #608: 2 _ 3 _ 9 _ 2 = 8 medium #619: 2 _ 3 _ 9 _ 9 = -3 medium #630: 2 _ 4 _ 2 _ 5 = 20 medium #639: 2 _ 4 _ 2 _ 8 = 9 medium #640: 2 _ 4 _ 2 _ 8 = -7 medium #641: 2 _ 4 _ 2 _ 9 = 10 medium #648: 2 _ 4 _ 3 _ 8 = 12 medium #654: 2 _ 4 _ 5 _ 6 = 15 medium #657: 2 _ 4 _ 6 _ 9 = 8 medium #660: 2 _ 4 _ 6 _ 9 = -4 medium #665: 2 _ 4 _ 6 _ 5 = 15 medium #666: 2 _ 4 _ 6 _ 7 = 10 medium #668: 2 _ 4 _ 6 _ 8 = 11 medium #669: 2 _ 4 _ 6 _ 8 = -5 medium #670: 2 _ 4 _ 6 _ 9 = -6 medium #684: 2 _ 4 _ 8 _ 5 = -4 medium #686: 2 _ 4 _ 8 _ 6 = -5 medium #687: 2 _ 4 _ 8 _ 7 = 8 medium #688: 2 _ 4 _ 8 _ 7 = -6 medium #689: 2 _ 4 _ 8 _ 8 = -7 medium #690: 2 _ 4 _ 8 _ 9 = 10 medium #695: 2 _ 4 _ 8 _ 3 = 12 medium #700: 2 _ 4 _ 8 _ 7 = 11 medium #701: 2 _ 4 _ 8 _ 8 = 12 medium #702: 2 _ 4 _ 8 _ 8 = -4 medium