1. Geoboards
Algebra and Geoboards

2. Coordinates
Think of your Geoboard as the 1st Quadrant
(0,0) x y

3. Coordinates Graph the following points on your Geoboard: Red dot (1,2)
Blue dot (5,3)
White dot (8,7)
(0,0) x y

4. Coordinates
We can also think of the Geoboard as 4 Quadrants
(0,0) x y

5. Coordinates Graph the following points on your Geoboard:
Red dot (-1,2)
Blue dot (3,-3)
White dot (-2,-3)
(0,0) x y
BINGO

6. Algebra and Pre-Algebra
We can use the Geoboard to help with graphing equations and determining slope:
Connect (-3,-3) and (3,3)
What is the slope of the line that connects these points? y x
(0,0)

7. Slope What is the slope of the line that passes through:
(2, -3) and (-4, 3)?
(0,0) x y

8. Algebra x y
Graph the following points on your Geoboard:
Red dot (-1,1)
Blue dot (3,-3)
Use a band to draw the line that goes through both points
(0,0)
What is the equation of the line that goes through the two points?
y=-x

9. Algebra
Graph the following line on your Geoboard:
y=2x-4
(0,0) x y

10. Algebra
Graph the following line on your Geoboard:
(0,0) x y

11. Algebra
Graph the following line on your Geoboard:
(0,0) x y

12. Algebra Connect (-3,-2) and (3,2)
What is the slope of the line that connects these points?
Connect (-2,2) and (2,-4)
What do we notice about the slopes? The lines? y x
(0,0)

13. Algebra Connect (-3,-2) and (3,2)
What is the slope of the line that connects these points?
Connect (-4,-1) and (2,3)
What do we notice about the slopes? The lines? y x
(0,0)

14. Algebra (2,0) What is the point of intersection?
Graph the following line on your Geoboard:
(0,0) x y
(2,0)
What is the point of intersection?

15. Questions? Suggestions?
Geoboards and Algebra
Questions?
Suggestions?

16. Geoboards, Tangrams, and Algebra
How can we relate the Geoboard and Tangrams with Algebra?

17. Geoboards and Tangrams
Use your Geoboard and bands to form a special geometric shape following the steps below.
Band together: (0,0) (0,8) (8,8) and (8,0)
Band together: (0,8) and (8,0)
Band together: (0,4) and (4,0)
Band together: (2,2) and (8,8)
Band together: (2,2) and (2,6)
Band together: (6,2) and (4,0)

18. Geoboards and Tangrams
Here is a grid showing tangram pieces: What are the coordinates of the colored dots that mark out the tangram? A B C D E F G H I