Sixth Grade · Math · week 14

Opposites and absolute value

Identify the opposite of a number and find absolute value as distance from zero, and use absolute value in real contexts.

Every number has an opposite: the same distance from zero, but on the other side. The opposite of 5 is −5; the opposite of −8 is 8. A number and its opposite always add to 0.

Absolute value is the DISTANCE a number is from zero on the number line - always zero or positive, because distance is never negative. The symbol is two straight bars: |−7| = 7.

Absolute value answers "how far," not "which direction." |5| = 5 and |−5| = 5, because both are 5 steps from zero.

📋 For the teacher
Teach it (10–15 min):
  • Physically walk out a number line on the floor with tape or chalk and measure steps to zero for absolute value.
  • Keep the two ideas distinct with different questions: "what number is it?" for opposite, versus "how far is it?" for absolute value.
  • Use temperature-difference contexts: "5 degrees below zero" has an absolute value of 5, even though the temperature itself is negative.
  • Point out that absolute value is never negative - if an answer comes out negative, something went wrong.
Talk about it:
  • What is the difference between the opposite of a number and its absolute value?
  • Why can absolute value never be negative?
  • Can two different numbers have the same absolute value? Give an example.

Mastery looks like: They correctly compute absolute value as distance from zero and distinguish it from finding a number's opposite.

Common stumbles: Treating |−7| as −7 instead of 7; confusing "opposite" with "absolute value" as though they were the same operation.

Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
Records attendance + 15 min of Math for this learner.
← Back to todayAll coursesYear planner