Lesson 2.1: Representing Integers
Focus: Use colored tiles to represent integers.
What is an integer?
⇒
Look at the photos at the top of p. 52. How do these 2 pictures represent integers?
2)
1)
Negative integers represent temperatures "below/above" (circle) zero.
Positive integers represent temperatures "below/above" (circle) zero.
Tiles can be used to represent whole numbers
•
Use yellow tiles to represent positive numbers
+1
•
Use red tiles to represent negative numbers
-1
Examples:
a) What integer does this represent?
______
b) What integer does this represent?
______
How can you tell if the tiles represent a positive or negative number?
•
If there are more yellow than red tiles, the integer is __________
•
If there are more red than yellow tiles, the integer is __________
Example: What integer does this represent? _______
How do you know?
How do you represent zero?
•
•
Equal number of red and yellow tiles
Called a ______________
+1
-1
+1
+1
-1
-1
How would you represent the average annual temperature of Antarctica with tiles?
How would you represent the average annual temperature of Antarctica with tiles?
How would you represent the average annual temperature of Ethiopia with tiles?
How would you represent the average annual temperature of Ethiopia with tiles?
NOTE: Different colors of tiles can be used to represent positive and
negative integers. For example you can use green tiles to represent
positive integers and blue tiles to represent negative integers
Explore p. 52
- Materials needed:
9 or 10 colored tiles or counters each
A) How many different integers can you model with 9 tiles?
B) How many different integers can you model with 10 tiles?
Explore cont. :
As you are sorting your tiles think and write down the answer to the following
questions:
1) How can you tell if the model represents a positive or negative integer?
2) Can you model zero with 10 tiles? Why or why not?
3) Can you model zero with 9 tiles?
Can you use coloured tiles to model 0 in three different ways?
Show three ways.
1)
2)
3)
Connect: We can model any integer in many ways.
- Using colored tiles and model -4 in three different ways.
1)
2)
3)
Homework: p. 54 #1, 2, 4, 5, 6
3)
Integer: _______
Red
Yellow
Integer