Which number line shows the solution to 6 + (−6)? A number line is shown from negative 12 to 0 to positive 12. There are increments of 2 on either side of the number line. An arrow pointing from 0 to negative 6 is shown. Above this, another arrow pointing from negative 6 to negative 12 is shown. A number line is shown from negative 12 to 0 to positive 12. There are increments of 2 on either side of the number line. An arrow pointing from 0 to 6 is shown. Above this, another arrow pointing from 6 to 0 is shown. A number line is shown from negative 12 to 0 to positive 12. There are increments of 2 on either side of the number line. An arrow pointing from 0 to negative 6 is shown. Above this, another arrow pointing from negative 6 to positive 6 is shown. A number line is shown from negative 12 to 0 to positive 12. There are increments of 2 on either side of the number line. An arrow pointing from 0 to 6 is shown. Above this, another arrow pointing from 6 to 12 is shown.