� Reading number lines
Write the inequality shown by each number line. Watch for open and closed circles.
� Matching diagrams
Pick the number line that matches the inequality.
� Solving — one-step
Solve just like an equation: whatever you do to one side, do to the other.
� Solving — two-step
Undo addition or subtraction first, then multiplication or division.
� Double inequalities
Two boundaries at once: read them from a number line, or list the integers in between.
Key rules
Open circle (○) means the value is not included: use \(\lt\) or \(\gt\).
Closed circle (●) means the value is included: use \(\le\) or \(\ge\).
Solving: treat it like an equation — whatever you do to one side, do to the other.
The flip rule: if you multiply or divide both sides by a negative number, the inequality sign flips direction.
Double inequalities: do the same thing to all three parts.