Subtraction

To complete this activity:

  1. Click the minus button at the bottom of the manipulative to view a subtraction problem.
     
  2. Use your own words to describe the question being asked by the number sentence.
  3. A subtraction sentence might take the form "how many are left when you separate (number of things) from (number of things)?" For example, "how many are left when you separate 5 from 9?"

  4. Students should read the number sentence before they click on the Go button.
  5. What does the minus symbol abbreviate? What does the equals sign mean?

  6. After observing the number-line representation of a number sentence, students should state an answer to the original question using the form "(number of things) are left when you separate (number of things) from (number of things). For example, "there are 4 left when you separate 5 from 9."

Students should be able to define the operation of subtraction and describe in words what is being asked for in a number sentence question.