a, -37 + 54 + ( -70 ) + ( -163 ) + 246
= - 37 + 54 - 70 - 163 + 246
= ( 54 + 246 ) - ( 37 + 163 ) - 70
= 300 - 200 - 70
= 100 - 70
= 30
b, - 359 + 191 + ( -123 ) + 350 + ( -172 )
= - 359 + 191 - 123 + 350 - 172
= ( 350 - 359 ) + 191 - ( 123 + 172 )
= - 9 + 191 - 295
= 191 - 304
= -113
c, - 69 + 53 + 46 + ( -94 ) + 14 + 78
= - 69 + 53 + 46 - 94 + 14 + 78
= ( 53 + 46 ) - 69 - 94 + ( 14 + 78 )
= 100 - 69 - 94 + 92
= ( 100 - 69 ) + ( 92 - 94 )
= 31 + ( - 2 )
= 31 - 2
= 29
d, 13 - 12 + 11 + 10 - 9 + 8 - 7 - 4 + 5 - 4 + 3 + 2 - 1
= ( 13 - 12 ) + 11 + ( 10 - 9 ) + ( 8 - 7 ) + ( 5 - 4 ) + ( 3 - 4 ) + ( 2 - 1 )
= 1 + 11 + 1 + 1 + 1 - 1 + 1
= 15
