Negative Numbers

• Draw a large number line and place it in a prominent place in the room for students to refer to throughout the unit.
• Students may not have used a number line in a while, so it may be a good idea to have them do some operations with just positive numbers to refresh their memories.
• Have the students make their own number lines to use when ordering negative numbers and when doing operations with negative numbers.
• Whenever possible provide real-world models of negative numbers, such as taking steps forward or back.
• Students often become confused with the terms "minus," "negative" and "opposite." Minus refers to the operation of subtraction. Negative is the sign of a number. The expression 5 – (2) should be read as "5 minus negative 2." Opposite is used to refer to the number which has the opposite sign. Hence, 2 is the opposite of ⁺2 and ⁺7 is the opposite of 7.
• Students should justify their answers for operations with negative numbers by drawing a number line and indicating movement on it with arrows.
• Give students a positive or negative number and ask them to give you two numbers, one positive and one negative, whose sum is the given number. For example, given the number 3, it could be the sum of 8 and ⁺5. Do the same for subtraction.

Placing Negative Numbers
on a Number Line

• Introducing the Concept
• Developing the Concept

Adding and Subtracting
with Negative Numbers

• Introducing the Concept
• Developing the Concept