What you’ll learn
Understand opposites on a number line.
Key idea
Nonzero opposites have equal distance from zero and lie on opposite sides.
Two identical nonzero points have equal magnitudes but are not opposites; reflection keeps distance and reverses side.
Worked example
Classify examples and non-examples for the concept 'Understand opposites on a number line'.
Are -45 and -45 opposites on a number line? Classify using both their distances from zero and their sides of zero.
- The opposite must remain 45 units from zero but switch side.
- Reflecting -45 gives +45; the proposed partner does not match.
Answer: Non-example — opposites of -45 have the same magnitude on the other side, at +45.
Quick Check
Classify examples and non-examples for the concept 'Understand opposites on a number line'.
Are -20 and +20 opposites on a number line? Classify using both their distances from zero and their sides of zero.