Two or More Lines
10 min
Narrative
The purpose of this How Many Do You See? is to allow students to use subitizing or grouping strategies to describe the image they see. Listen for the language students use to describe how they count and define the line segments in the image.
Launch
- Groups of 2
- “How many do you see? How do you see them?”
- Display the image.
- 1 minute: quiet think time
Teacher Instructions
- Display the image.
- “Discuss your thinking with your partner.”
- 1 minute: partner discussion
- Record responses.
Student Task
How many line segments do you see? How do you see them?
image with many line segments. 4 line segments join to form a rectangle. 1 line segment to create the diagonal of the rectangle. 2 more line segments connect to the bottom side of the rectangle to form a right triangle. 2 more line segments connect to the right side of the rectangle to form another right triangle.
Sample Response
- 7 line segments. Sample response:
- There are 2 long segments that make a plus sign, 1 horizontal segment, and 1 vertical segment in the upper left, and 3 slanted segments.
- 9 line segments. Sample responses:
- There are 4 triangles with 3 segments each, which means 12 sides. The triangle in the middle shares all 3 sides with the other triangles, so we need to subtract 3 to avoid double counting those segments.
- There are 3 vertical segments, 3 horizontal segments, and 3 slanted segments.
- 11 line segments. Sample response:
- There are 4 horizontal segments (3 short, 1 long), 4 vertical segments (3 short, 1 long), and 3 slanted segments.
Activity Synthesis (Teacher Notes)
- “How many line segments does this image have? Is there more than one way to answer this question?” (7, 9, 11. Yes, depending on if we count the segments that cross as 2 intersecting segments or 4 segments that share a single vertex.)
- “How do we determine where line segments start and end?” (They are between pairs of points or vertices in the figure.)
- Consider asking:
- “Who can restate the way _____ saw the figure in different words?”
- “Did anyone see the figure the same way but would explain it differently?”
- “Does anyone want to add an observation to the way _____ saw the figure?”
Standards
Addressing
- 4.G.1·Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
- 4.G.A.1·Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
15 min
20 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Two or More Lines
10 min
Narrative
The purpose of this How Many Do You See? is to allow students to use subitizing or grouping strategies to describe the image they see. Listen for the language students use to describe how they count and define the line segments in the image.
Launch
- Groups of 2
- “How many do you see? How do you see them?”
- Display the image.
- 1 minute: quiet think time
Teacher Instructions
- Display the image.
- “Discuss your thinking with your partner.”
- 1 minute: partner discussion
- Record responses.
Student Task
How many line segments do you see? How do you see them?
image with many line segments. 4 line segments join to form a rectangle. 1 line segment to create the diagonal of the rectangle. 2 more line segments connect to the bottom side of the rectangle to form a right triangle. 2 more line segments connect to the right side of the rectangle to form another right triangle.
Sample Response
- 7 line segments. Sample response:
- There are 2 long segments that make a plus sign, 1 horizontal segment, and 1 vertical segment in the upper left, and 3 slanted segments.
- 9 line segments. Sample responses:
- There are 4 triangles with 3 segments each, which means 12 sides. The triangle in the middle shares all 3 sides with the other triangles, so we need to subtract 3 to avoid double counting those segments.
- There are 3 vertical segments, 3 horizontal segments, and 3 slanted segments.
- 11 line segments. Sample response:
- There are 4 horizontal segments (3 short, 1 long), 4 vertical segments (3 short, 1 long), and 3 slanted segments.
Activity Synthesis (Teacher Notes)
- “How many line segments does this image have? Is there more than one way to answer this question?” (7, 9, 11. Yes, depending on if we count the segments that cross as 2 intersecting segments or 4 segments that share a single vertex.)
- “How do we determine where line segments start and end?” (They are between pairs of points or vertices in the figure.)
- Consider asking:
- “Who can restate the way _____ saw the figure in different words?”
- “Did anyone see the figure the same way but would explain it differently?”
- “Does anyone want to add an observation to the way _____ saw the figure?”
Standards
Addressing
- 4.G.1·Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
- 4.G.A.1·Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.