Math
Forgetting to Flip the Inequality When Dividing by a Negative
Dividing or multiplying both sides of an inequality by a negative without reversing the sign.
Quick check
Why students make it
Equations never need the sign changed, so the habit carries over. Inequalities are different because a negative factor reverses the order of the number line.
The rule done right
When you multiply or divide both sides of an inequality by a negative number, flip the inequality sign.
Related resources
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Math, Sign when multiplying or dividing integers Infographic -
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Math, Absolute Value Equations and Inequalities Infographic -
Math, Absolute Value Infographic - Inequalities & Absolute Value Cheat Sheet
- Sign when multiplying or dividing integers Memory Aid Cheat Sheet
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- Solving and Graphing Inequalities Worksheet
- Sign When Multiplying or Dividing Integers Practice Worksheet
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- Inequalities & Interval Grapher Tool
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- Integer Operations & Absolute Value Lab Lab
- Equation Balance & Intro Algebra Lab Lab
- Systems of Equations Lab Lab