Lesson 7.67.6 Small Group · Group 1
Start hereWords, worked example, and sentence starters
Learning target With my small group, I can find the distance between two points on the coordinate plane using absolute value — one step at a time, with support.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| DistanceSpanish: Distancia | How far apart two points are. It is never negative. | always a positive length |
| Absolute valueSpanish: Valor absoluto | How far a number is from zero. It is never negative. | |−7| = 7 |
| Horizontal distanceSpanish: Distancia horizontal | How far apart two points are going left or right. | uses the x-coordinates |
| Vertical distanceSpanish: Distancia vertical | How far apart two points are going up or down. | uses the y-coordinates |
| Coordinate planeSpanish: Plano cartesiano | A grid with a line going across and a line going up to plot points. | x-axis across, y-axis up |
| IntegerSpanish: Número entero | Whole numbers and their opposites, like -2, -1, 0, 1, 2. | ..., -3, -2, -1, 0, 1, 2, 3, ... |
How it worksWorked examplefinding the distance between two points on a vertical line
These numbers are not on your problems. The steps are. Follow them with your own numbers.
On a map where each unit is one kilometer, find the distance from J(−4.5, 8.5) to K(−4.5, −3.5).
- The x-coordinates match, so both points sit on one vertical line.
- The y-coordinates have different signs, so the trip crosses the x-axis.
- Distance from 0 for each y-coordinate: 8.5 = 8.5 and −3.5 = 3.5
- Join the two distances: 8.5 + 3.5 = 12
Answer: The points are 12 units apart, so the trip is 12 kilometers straight up and down.
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
On the same map, find the distance from P(6.5, 2.5) to Q(−9.5, 2.5).
- The -coordinates match, so both points sit on one line.
- The x-coordinates have signs, so the trip crosses an axis.
- Distance from 0 for each x-coordinate: 6.5 = and −9.5 =
- Join the two distances: + =
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The two points share the -coordinate, so the segment runs .
- I used absolute value because .
- The points sit on sides of the axis, so I the two distances.
- The distance is units, which means on this map.
Word bank distanceabsolute valuehorizontalverticalcoordinate planeaxisunitsaddsubtractx-coordinatey-coordinatesegment
Watch outA common mistake
A common mistake in Distance on the Coordinate Plane is subtracting the coordinates as if both points were on the same side of zero, instead of adding their absolute values when the points are on opposite sides. For example, to find the distance between (-6, 3) and (2, 3), a student might subtract 6 − 2 = 4, but since -6 and 2 are on opposite sides of zero, the absolute values must be added instead: |-6| + |2| = 6 + 2 = 8. The correct distance is 8 units, not 4. Before you submit, ask: 'Are these two points on opposite sides of zero — and if so, did I add the absolute values instead of subtracting?'
Lesson 7.67.6 Small Group · Group 1
Group 1Supported practice
Learning target With my small group, I can find the distance between two points on the coordinate plane using absolute value — one step at a time, with support.
-
1Complete each step, then write the final answer.
2 units to the y-axis, then 6 more. Find the distance between (−2, 4) and (6, 4).
- 1Which coordinate is the same?
- 2Are −2 and 6 on the same side of 0?
- 3Add the distances from 0: |−2| + |6|. What is the distance?
Final answer: -
2Complete each step, then write the final answer.
This time the line goes up and down. Find the distance between (3, −4) and (3, 2).
- 1Which coordinate is the same?
- 2How far is each point from the x-axis?
- 3The points are on opposite sides of 0. Find the distance.
Final answer: -
3Complete each step, then write the final answer.
Find the distance between (1, 5) and (7, 5).
Show your workHint Both x-values are positive. They are on the same side of 0, so subtract.
Final answer: -
4Complete each step, then write the final answer.
Find the distance between (−4, −3) and (−4, 6).
Show your workHint The y-values have different signs. 0 is between them, so add the distances from 0.
Final answer: -
5Complete each step, then write the final answer.
On a map, the school is at (−5, −2) and the park is at (3, −2). Each unit is 1 block. How many blocks apart are they?
Show your workHint Both points have y = −2. Look at the signs of the x-values.
Final answer: -
6Complete each step, then write the final answer.
Leo finds the distance from (2, −1) to (2, −7). He adds 1 + 7 = 8. Is he right? What is the distance?
Show your workHint Are −1 and −7 on the same side of 0, or on opposite sides?
Final answer:
Explain your thinkingHow do you decide to add or subtract the distances from 0? Use Leo's mistake to explain.
Sentence starter When both points are on the same side of 0, I ___. · Leo should ___ because ___.