12 - 3 + 4 + 54 - 349 = 9 + 4 + 54 - 349 = 13 + 54 - 349 = 67 - 349 = -282
( 5° + 51 + 52 + 53 + 54 ) ÷ ( 71.5 + 6.71 ) = ( 5° + 210 ) ÷ 78.21 = ( 5° + 210 ) ÷ 7.821/100 = ( 5° + 210 ) • 100/7.821 = 100•5°/7.821 + 7.000/2.607 = 500°/7.821 + 7.000/2.607