Coordinate Plane — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
To plot (5, 3), start at the origin and move 5 units up, then 3 units right.
Corrected: To plot (5, 3), start at the origin and move 5 units right, then 3 units up.
The corrected sentence is: "To plot (5, 3), start at the origin and move 5 units right, then 3 units up.". The original sentence "To plot (5, 3), start at the origin and move 5 units up, then 3 units right." contained an error that needed to be fixed.
2. Fix the sentence:
The horizontal axis on a coordinate plane is called the y-axis.
Corrected: The horizontal axis on a coordinate plane is called the x-axis.
The corrected sentence is: "The horizontal axis on a coordinate plane is called the x-axis.". The original sentence "The horizontal axis on a coordinate plane is called the y-axis." contained an error that needed to be fixed.
3. Fix the sentence:
The point (0, 4) is plotted 4 units to the right of the origin.
Corrected: The point (0, 4) is plotted 4 units up from the origin.
The corrected sentence is: "The point (0, 4) is plotted 4 units up from the origin.". The original sentence "The point (0, 4) is plotted 4 units to the right of the origin." contained an error that needed to be fixed.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The horizontal axis is called the x-axis.
The x-axis is the horizontal (left-right) axis on a coordinate plane. Moving right increases x; moving left decreases x.
2. The vertical axis is called the y-axis.
The y-axis is the vertical (up-down) axis on a coordinate plane. Moving up increases y; moving down decreases y.
3. To plot (3, 7), move 3 units right from the origin.
The first number in an ordered pair is the x-coordinate — it tells you how many units to move right (or left if negative) from the origin.
4. To plot (3, 7), move 7 units up from the origin.
The second number in an ordered pair is the y-coordinate — it tells you how many units to move up (or down if negative) after moving horizontally.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Describe the steps to plot the point (6, 4) on a coordinate plane.
Sample answer: Start at the origin (0, 0). Move 6 units right along the x-axis. Then move 4 units up parallel to the y-axis. Mark and label the point (6, 4) at that location.
Plotting follows two steps: move horizontally (x-value), then vertically (y-value) from that position. Always start from the origin.
2. Two points are plotted: P at (2, 5) and Q at (2, 1). What do you notice about their x-coordinates and what does that tell you about their positions?
Sample answer: Both points have the same x-coordinate of 2, so they are both 2 units right of the origin. They lie on the same vertical line. Point P is higher on the grid than Point Q.
Points with the same x-coordinate are vertically aligned — they share the same horizontal position and fall on the same vertical line.