A "New Set of Numbers" (An Introduction of Integers)

Barbara Barlow                 Caldwell School
10533 S. Sangamon              8546 S. Cregier
Chicago IL 60643               Chicago IL 60617
312-779-5726                   312-535-6666

Objective:

    Students of the sixth grade will be able to add and subtract positive and 
negative integers.  Incidentally, negative numbers were invented by the Chinese.  

Materials Needed:

    Group of fifteen students
    Numbers with positive signs (written on construction paper) 
    Numbers with negative signs (written on construction paper)
    A large zero (written on construction paper)
    
    Two paper bags (one labeled positive and one labeled negative) with 
directions inside which tell the students what to do on the number line.  Some 
examples are: 

     Take 3 negative steps         Add negative 3
     Take 5 positive steps         Subtract positive 4

Strategies:

    Review of number line on chalkboard: 
    Number line will be made, using students as the numbers.  Students to the 
right of the zero will be called positive integers and all students to the left 
of the zero will be called negative integers.  The distance from the zero to the 
next point (going in either direction) will be called the "unit distance."  Each 
student will tell how many units they are from zero.  The students will now 
receive their signed numbers written on construction paper. 
    The "additive inverse" concept will now be introduced and explained.  The 
students will then find their additive inverse. 
    Students will move a given number of units (to the left or to the right) to 
represent the process of adding and subtracting integers.  They will then name 
their new value. 
    Students will now pull directions from a bag and each take turns moving in 
the given direction; Ex: Take 2 positive steps. 
    Students will be given a sheet of problems to practice adding and 
subtracting integers. 
    
Performance Assessment:

    Students will solve a puzzle by adding and subtracting integers.

Conclusion:

    After presenting this lesson, students will have a greater understanding of 
integers and the concept of positive and negative numbers.  They will also know 
how to add and subtract integers.