Step-by-step explanation: To find the sum p + q using a number line with p = -19 and q = 12.1, follow these steps:
1. Start at the number -19 on the number line.
2. Move to the right by 12 spaces (representing 12 whole units) to reach -7.
3. Continue moving to the right by 0.1 spaces (representing 0.1, which is 1/10) from -7. This will take you to a point slightly to the left of -6.9.
4. The final position on the number line, approximately -6.9, represents the sum p + q.
So, the sum of -19 and 12.1 is approximately -6.9, as shown on the number line.