GED Math: Graphing Points and the Coordinate Plane Grid

Hey guys! I got something about the GED math test that you gotta know. The test’s got mostly multiple choice questions, about 80%. But there’s 20% of the questions that ain’t multiple choice, in those questions, you got two different types. I’m gonna give you the low-down on one of em, the “coordinate plane grid.” You prolly got no idea what dat is. Well, here’s the 411.

Here’s what the coordinate plane answer grid’ll look like on your GED answer sheet:

So, what’s it for? The questions that use this grid ask you to graph a point. Just a dot. That’s all. The point is, where is it? That’s all they want to know. One of these 49 dots is the answer. Well, that’s a big margin for guessin’, jus’ 2% chance to get it right. (How’d I figure the percent chance? If you mark one bubble outta 49 bubbles, that’s a 1 in 49 chance of getting the right bubble… and 49 rounds to 50, multiply both sides by 2 and you got a 2 in 100 chance. That’s 2%. Okay, that’s a sidetrack.)

A “coordinate plane” is jus’ a graph of where something is in comparison to two lines, an x-axis (a line going right and left), and a y-axis (a line going up and down). The two axes are marked “x” and “y” on your graph.

A point you’d want to graph on here would be written like this: (3, -2). The first number is the x, and the second number is the y. To find the point, go to +3 on the x axis:

And then go DOWN 2 (so you’re across from -2 on the y axis):

The point you’re at is (3, -2).

Pretty easy. On the test, the values of x or y can only be 6, 5, 4, 3, 2, 1, 0, -1, -2, -3, -4, -5, or -6. There won’t be any fractions, decimals, or other numbers. So, if you think you know the answer, but it doesn’t fit on the grid, try again!

Another thing, you’ll only fill in only one circle on the grid. The answer to the question will be one single point. Okay, try this GED practice question, using the coordinate plane grid:

In the equation y = 2x + 3, show the location of a point where x = -2.

How’d you do on this? Did you figure it out? They give you one part of the point, -2, but they don’t give you the whole thing. You’ve got to put -2 into the equation for x to find out what y is:

y = 2(-2) + 3

y = -4 + 3 (Hint: A negative number times a positive number gives you a negative number)

y = -1 (Hint: To add a negative and a positive number, subtract the numbers and then give it the sign of the BIGGER number, so -4 + 3 = -1, but 4 + -3 = 1. Don’t let negative numbers throw you on the test!)

So, the point you want to graph is (-2, -1), like this:

Go learn that GED math!

For more information about the GED test and GED test preparation, visit The GED Academy at http://www.passGED.com.