Introducing Negative Numbers

By Vicki M. DePountis on Apr 24, 2017

Introducing negative numbers: Student will subtract integers to get a negative result. 

 

Addition and subtraction of positive rational numbers where result is < =0.

Materials

Students can make visual number line or Braille number line. Visual number lines can be made on large strips of card stock, at least 14” long. Place numbers every 1/2 inch to get at least +/- 14 on each side of the middle. Braille number lines are available through APH or can be made using glue, wiki sticks, or a Perkins brailler.

Procedure

  1. Using braille number lines, have students establish “zero” by finding the origin.
  2. Explain that adding means moving to the right on the number line. Have students add several integers by counting and share their answers.
  3. Explain that subtracting means moving to the left. Have students subtract several integers by counting to the left and share their answers.
  4. Provide examples where the answer leads to “0.”
  5. Provide examples where the answer leads to negative number.
  6. Discuss the meanings and applications of negative numbers. In what types of problems would they be relevant? Examples: money (IOUs), temperature, above/below ground.
  7. Have students solve problems where the starting number is positive and result is negative, where the starting number is negative and the result is positive, and where the result is zero. Have students complete similar operations with simple fractions and decimals. 
  ** Independent living skills may be addressed when topic is applied to temperature and spending.