Arithmetic Operator Puzzles

#481: 1 _ 9 _ 6 _ 3 = 2 easy #482: 1 _ 9 _ 7 _ 7 = 8 medium #483: 1 _ 9 _ 8 _ 4 = 19 hard #484: 1 _ 9 _ 8 _ 6 = 13 hard #485: 1 _ 9 _ 8 _ 2 = 13 hard #486: 1 _ 9 _ 8 _ 4 = 11 hard #487: 1 _ 9 _ 8 _ 2 = 5 easy #488: 1 _ 9 _ 8 _ 4 = 7 medium #489: 1 _ 9 _ 8 _ 4 = 18 hard #490: 1 _ 9 _ 9 _ 3 = 12 hard #491: 1 _ 9 _ 9 _ 3 = 6 medium #492: 1 _ 9 _ 9 _ 9 = 8 medium #493: 2 _ 1 _ 2 _ 8 = 6 easy #494: 2 _ 1 _ 2 _ 8 = -2 easy #495: 2 _ 1 _ 3 _ 9 = 5 easy #496: 2 _ 1 _ 3 _ 9 = -1 easy #497: 2 _ 2 _ 2 _ 4 = 1 easy #498: 2 _ 2 _ 2 _ 8 = 1 easy #499: 2 _ 2 _ 2 _ 3 = 7 easy #500: 2 _ 2 _ 2 _ 4 = 9 easy #501: 2 _ 2 _ 2 _ 6 = 13 medium #502: 2 _ 2 _ 2 _ 8 = 17 hard #503: 2 _ 2 _ 2 _ 9 = 19 hard #504: 2 _ 2 _ 2 _ 4 = -7 easy #505: 2 _ 2 _ 2 _ 5 = -9 easy #506: 2 _ 2 _ 2 _ 6 = 3 easy #507: 2 _ 2 _ 2 _ 8 = 4 easy #508: 2 _ 2 _ 3 _ 9 = 8 medium #509: 2 _ 2 _ 3 _ 9 = -4 medium #510: 2 _ 2 _ 3 _ 6 = 8 easy #511: 2 _ 2 _ 3 _ 2 = 7 easy #512: 2 _ 2 _ 3 _ 4 = 13 easy #513: 2 _ 2 _ 3 _ 5 = 16 medium #514: 2 _ 2 _ 3 _ 6 = 19 hard #515: 2 _ 2 _ 3 _ 3 = -8 easy #516: 2 _ 2 _ 4 _ 8 = 3 easy #517: 2 _ 2 _ 4 _ 6 = 5 easy #518: 2 _ 2 _ 4 _ 8 = 6 easy #519: 2 _ 2 _ 4 _ 8 = 1 easy #520: 2 _ 2 _ 4 _ 2 = 1 easy #521: 2 _ 2 _ 4 _ 8 = -2 easy #522: 2 _ 2 _ 4 _ 1 = 2 easy #523: 2 _ 2 _ 4 _ 3 = 4 easy #524: 2 _ 2 _ 4 _ 3 = -2 easy #525: 2 _ 2 _ 4 _ 4 = -3 easy #526: 2 _ 2 _ 4 _ 5 = 6 easy #527: 2 _ 2 _ 4 _ 5 = -4 easy #528: 2 _ 2 _ 4 _ 6 = 7 easy