Khan Academy Wiki
Number opposites
Opposites-on-the-number-line 256
Description
Exercise Name: Number opposites
Math Missions: 6th grade (U.S.) Math Mission, Arithmetic essentials Math Mission, Pre-algebra Math Mission, Mathematics I Math Mission
Types of Problems: 2

The Number opposites exercise appears under the 6th grade (U.S.) Math Mission, Arithmetic essentials Math Mission, Pre-algebra Math Mission and Mathematics I Math Mission. This exercise helps understanding of the similarities and differences between the concept of opposite and the negative sign.

Types of Problems[]

There are two types of problems in this exercise:

  1. Determine the correct point: The problem asks which of the labeled points on a number line is the solution to a question about opposites. The user is expected to find the correct point and select it from a multiple choice list.
    Number opposites

    Determine the correct point

  2. Find the opposite: This problem asks the users determine the opposite of a particular number. In this problem the user is asked to write the answer in a provided answer box.
    No2

    Find the opposite

Strategies[]

This problem is easy to get accuracy badges because opposites have many different representations but all take one step to find. The speed badges are also easy because to solve the problems in the exercise is rarely more than one step of reasoning.

  1. Be a little careful to distinguish whether the problem is asking for the opposite of the number given, or if it is asking to evaluate an expression with a negative sign.
  2. If user needs help, they can click the "Show me a worked example" button for an example.

Real-life Applications[]

  1. Negative numbers are used to represent land below sea level.
  2. Negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature.