Question

What's the difference between an opened circle on a number line and a closed circle. ( Pls give an example)

Answer 1

Open circle: used for < (less than) or > (greater than) because the number is not part of the solution.

Closed circle: used for ≥ (greater than or equal to) or ≤ (less than or equal to) because the number is part of the solution.

Shading:

Shade to the right for > or ≥

Shade to the left for < or ≤

Explanation:

2 < x < 5

Place a open circle on 2 with shading to the left and a open circle on 5 with shading to the right.

4 ≤ x ≤ 10

Place a closed circle on 4 with shading to the left and a closed circle on 10 with shading to the right.