x-axis : Horizontal number line that extends indefinitely in both directions from zero.(Positive-right, Negative-left)
y-axis : Vertical number line that extends indefinitely in both directions from zero. (Positive-up, Negative-down)
coordinate plane : The 2-dimensional plane oe flat surface that is created when the x-axis intersects with the y-axis . It forms a mapping grid that facilitates the location of an point or object by using coordinates. Also known as a coordinate grid and the Cartesian plane.
quadrant : Any of the four regions created when the x-axis intersects with the y-axis. They are usually labeled with Roman numerals such as Quadrant I, Quadrant II, III or IV.
Quadrant I (positive x, positive y)
Quadrant II (negative x, positive y)
Quadrant III (negative x, negative y)
Quadrant IV (positive x, negative y)
point of origin: The point where zero on the x -axis intersects zero on the y -axis.
The Bare Minimum to Plot CoordinArt
The first number (coordinate) in every ordered pair is the x-coordinate. The second number is always the y-coordinate.
Find the x value along the horizontal axis and then move up or down to the appropriate y value. Plot the point at this intersection. Be aware there are values between the grid lines values given and some points will end up in the space between the grid lines because that’s where the two values would intersect.
Using a straight edge connect the points as you go, but stop connecting when you come to the word STOP. Begin fresh with the next set of ordered pairs.
If you find yourself drawing a stray line through the design you have probably either mixed up the x and y coordinates, or overlooked whether a coordinate was positive or negative.
HINT for those new to plotting in all four quadrants:
Before beginning have students take out a highlighter (or borrow one) and highlight the NEGATIVE portion of the x- axis. Demonstrate for students with a document camera or using an overhead if possible.
Using that same highlighter....highlight ONLY the x coordinates on the instructions that are NEGATIVE. (Continue to demonstrate.)
Take a different color highlighter and highlight the NEGATIVE portion of the y - axis. (Students are good at sharing with each other to find a second color to use.)
Using this second color highlight ONLY the negative y-coordinates.
Quickly walk around to check that coordinate grids and instructions are highlighted correctly. (Have a few extra on hand for those who didn’t highlight as directed.)
Taking the time to do this helps call attention to the negative numbers and promotes more success right from the start.
WHERE WAS I?: It is important for students to keep track where they are on the coordinate sheet as the plot the points. It is best to make a little check in front of the ordered pair as opposed to drawing a line through each one. Drawing through the numbers prohibits students from easily looking back at them to correct a misplotted point when they realize they made a mistake.
COLORING TIP: When coloring faces begin with a much lighter shade than you think you want. This gives you room to build depth to the face by adding darker and darker colors as needed. You can go over light colors with success, but not the other way around. Building light to dark will give 3-dimensional feel to the faces. This technique is the same whether you are coloring a caucasian or dark, African American face. Selecting only a dark color and coloring evenly with it will result in a very flat, 2-dimensional face. This is diappointing to students after their hard work of plotting all the points!
STRAIGHT EDGE TIP: A 6-inch ruler or protractor works great. I prefer my little 6-inch ruler to a full 12-inch one because it is small enough to quickly flip around any way I need.
Much more to come! Please be sure to check back. Thank you.