1 + 1 + 1 + 1

= ( 1 + 1 ) + ( 1 + 1 )

= 2 + 2

= 4

1 + 1 - 1 + 1 + 2 -3

= 2 - 1 + 1 + 2 - 3

= 1 + 1 + 2 - 3

= 2 + 2 - 3

= 4 - 3 

= 1

1 + 1 = 2

4 + 3 + 7 + 5

= ( 4 + 3 ) + ( 7 + 5 )

= 7 + 12

= 19

1 + 1 = 2

9 + 8 = 17

99 + 1 = 100

1 + 1+ 6 + 7 + 5 + 8 + 5 + 8 + 9 + 6 + 8 + 9 + 9 + 67

= ( 1 + 1 ) + ( 6 + 7 ) + ( 5 + 8 ) + ( 5 + 8 ) + ( 9 + 6 ) + ( 8 + 9 ) + ( 9 + 67 )

= 2 + 13 + 13 + 13 + 15 + 17 + 76

= 15 + 26 + 32 + 76

= 41 + 108

= 149

1 + 1 = 2