Practice Set · Part 1
Ordered Pairs in All Four Quadrants
Pick up where we left off
Where we left off
Our goal: I can plot ordered pairs in all four quadrants of the coordinate plane, explain what each part stands for, and build one for a situation I have not seen before.
The big idea: The signs of the coordinates name the quadrant, and a coordinate of 0 puts the point on an axis, in no quadrant.
Model to copy — Example 1 · From directions to a point
- Point A is 4 units left of the y-axis and 2.5 units down from the x-axis. Name point A and its quadrant.
- Turn left 4 into an x-coordinate: left 4 → x = −4
- Turn down 2.5 into a y-coordinate: down 2.5 → y = −2.5
- Write the ordered pair, x first: (−4, −2.5)
- Use the signs to name the quadrant: (−, −) → Quadrant III
- Point A is (−4, −2.5). It is in Quadrant III.
- Which quadrant is the point (0, −5) in?
- Read x. Do not move left or right: x = 0
- Read y. Move down 5 units: y = −5 → down 5
- Decide if the point is in a quadrant: on the y-axis → no quadrant
- (0, −5) is on the y-axis. It is not in any quadrant.
Start here
You did these with your group. Now do them on your own — the model above is yours to copy.
- 1
Same stepsFinish what the group started. Use the model above, step for step.
Try it together — then prove it: Plot the point (−5, 2). Name the quadrant it is in. Which way do we move for x = −5 and for y = 2? (Left 5, then up 2.) Which quadrant is (−5, 2) in? (Quadrant II) Why is (2, −5) in a different quadrant than (−5, 2)? ((2, −5) goes right 2 and down 5. That is Quadrant IV, not Quadrant II.)Show your work - 2
Warm restartA rectangle has vertices (1, 1), (7, 1), (7, 4) and (1, 4). How long is the bottom side?
- A3 units
- B4 units
- C6 units
- D8 units
How do you know?
- 3
Warm restartUsing that same rectangle — (1, 1), (7, 1), (7, 4), (1, 4) — what is its area?
- A9 square units
- B18 square units
- C18 units
- D24 square units
How do you know?
- 4
Warm restartA square has vertices (−2, −2), (2, −2), (2, 2) and (−2, 2). What is its perimeter?
- A4 units
- B8 units
- C16 units
- D16 square units
How do you know?
Practice Set · Part 2
Ordered Pairs in All Four Quadrants
Keep going
You answered these out loud. Now write them.
Answer, then say how you know — the reason is the part that counts.
- 5
Think it throughWhich quadrant is the library (−3, 4) in?
- AQuadrant I
- BQuadrant III
- CQuadrant II
- DQuadrant IV
Why is that the answer?
- 6
Think it throughWhich quadrant is the park (5, −2) in?
- AQuadrant I
- BQuadrant IV
- CQuadrant II
- DQuadrant III
How do you know? Give a second reason as well.
- 7
Think it throughWhich location is in Quadrant III?
- ACity Hall (0, 0)
- BThe school (2, 3)
- CThe library (−3, 4)
- DThe hospital (−4, −1)
Explain your thinking. What would have to change for a different choice to be right?
- 8
Back to the modelHow do the signs of the x- and y-coordinates tell you which quadrant a point is in?
Practice Set · Part 3
Ordered Pairs in All Four Quadrants
Words and reasoning
Word bank · Banco de palabras
Use the words
Fill each blank with a word from the bank.
- One of the four regions of the coordinate plane, numbered I to IV, is a ___.
- A coordinate less than zero, which places a point left of or below the origin, is a ___.
- A flip of a point over an axis is a ___.
- One of the two number lines, the x-axis or y-axis, that form the grid is an ___.
Explain the thinking
- 9
Find the mistakeAnother student made this exact mistake in this lesson. Explain why it is wrong, then write what they should have done.
The mistake: A common mistake in Ordered Pairs in All Four Quadrants is matching each sign to the wrong axis — for example, seeing (-2, 5) and thinking "the x is negative so I move DOWN, and the y is positive so I move RIGHT," which lands the point in Quadrant IV. - 10
Say morePlot (-3, -4). Which quadrant is it in, and how do the negative coordinates change the directions you move from the origin?
- 11
Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: A colorful eight-petaled flower design sits on a coordinate grid. An orange octagon is centered on the origin O, four maroon hexagon petals point straight up, down, left, and right along the axes, and four teal petals fill the space between them.
Show your work
Practice Set · Part 4
Ordered Pairs in All Four Quadrants
Show what you know
Last check
These two come from Lesson 7.7. If they are shaky, that is the lesson to revisit — not this one.
- 12
Show what you knowExplain your thinking — A point has a negative x-coordinate and a negative y-coordinate. Which quadrant is it in?
- AQuadrant III
- BQuadrant I
- CQuadrant II
- DQuadrant IV
Explain your choice.
- 13
From Lesson 7.7Explain your thinking — A rectangle has vertices (-1, 4), (5, 4), (5, 1), (-1, 1). What is its perimeter?
- A6 units
- B9 units
- C18 units
- D18 square units
How do you know?
- 14
From Lesson 7.7The park's length is 800 feet, and each grid unit represents 100 feet. How many units below the known vertices do the new corners sit?
- A0.8 units
- B8 units
- C80 units
- D800 units
How do you know?
Be honest — this tells your teacher what to do next
| I can… | Not yet | Getting there | Got it |
|---|---|---|---|
| I can plot ordered pairs in all four quadrants of the coordinate plane, explain what each part stands for, and build one for a situation I have not seen before. | |||
| I can explain why it works: The signs of the coordinates name the quadrant, and a coordinate of 0 puts the point on an axis… | |||
| I can justify my answer to a skeptic and connect it to a second strategy or representation. |
One question I want to ask my group next time