Number Line and Inequality

Summary and Exam Tips for Number Line and Inequality

Number Line and Inequality is a subtopic of Number, which falls under the subject Mathematics in the IB MYP curriculum. This topic involves understanding how to solve inequalities and represent them on a number line. Key symbols include $>$ for "more than", $<$ for "less than", $\geq$ for "more than or equal to", and $\leq$ for "less than or equal to". Solving inequalities is akin to solving equations, with a few additional rules. It's crucial to move all variables to one side and constants to the other, using inverse operations as needed. A critical point to remember is that multiplying or dividing by a negative number reverses the inequality sign. For example, solving $4 - 2x < 2$ results in $x > 1$, and solving $2(x + 1) > x - 7$ results in $x > -9$. Once solutions are found, they can be represented on a number line, where closed circles indicate numbers included ($\geq$, $\leq$) and open circles indicate numbers not included ($>$, $<$).

Exam Tips

• Understand the Symbols: Familiarize yourself with inequality symbols and their meanings to avoid confusion during exams.
• Practice Solving Inequalities: Regularly practice moving terms and using inverse operations to solve inequalities efficiently.
• Remember the Sign Rule: Always remember that multiplying or dividing by a negative number reverses the inequality sign.
• Use Number Lines: Visualize solutions on a number line to ensure clarity in representing inequalities.
• Check Your Work: After solving, substitute values back into the original inequality to verify your solution is correct.