Unit 7 · Standard 6.EE.8
Graph Inequalities
Key Vocabulary Level 1 support
Picture first, then the word, then a plain-language meaning. Say each word out loud.
A horizontal line with marks at 0, 1, 2, 3, ... showing where values fall
Number line
A line with numbers in order. You use it to show answers.
x > 5: open circle at 5 means 5 itself is NOT a solution, but 5.1, 6, 7, ... are
Open circle
An empty circle showing a number is NOT included.
x ≥ 5: closed circle at 5 means 5 IS a solution, and so are 6, 7, 8, ...
Closed circle
A filled-in circle showing a number IS included.
For x > 3, the solution set includes 3.1, 4, 5, 10, 100 — any number greater than 3
Solution set
All the numbers that make the inequality true.
Key Ideas & Notes
- Detective Okafor is building a timeline.
- The suspect was seen at the scene no earlier than 2:00 PM, meaning the arrival time t satisfies t ≥ 2.
- She needs to plot this on a timeline to share with her team.
- How should she mark the number line?
- Graph each inequality on the number line. Decide whether to use an open or closed circle, then shade in the correct direction.
Think About It
- What does 'no earlier than 2:00 PM' mean about the time?
- Should 2:00 PM itself be included?
- Which direction on the number line would you shade?
My Notes
Guided Examples
Example 1
Which graph represents x < 5?
Solution: x < 5 means 5 is NOT included (open circle) and values less than 5 are shaded (left).
Answer: A. Open circle at 5, shaded left
Example 2
Which graph represents x ≥ 3?
Solution: x ≥ 3 means 3 IS included (closed circle) and values greater than or equal to 3 are shaded (right).
Answer: A. Closed circle at 3, shaded right
Example 3
Which graph represents x > 8?
Solution: x > 8 means 8 is NOT included (open circle) and values greater than 8 are shaded to the right.
Answer: A. Open circle at 8, shaded right
Write About the Math The Writing Revolution
I can explain my graph using the words number line, open circle, closed circle, and solution set.
1. Kernel Sentence subject + verb
Model: Number line is a line with numbers in order. You use it to show answers.Recta numérica es una línea con números en orden. La usas para mostrar respuestas.
Write a kernel sentence about number line. Use a subject and a verb.Escribe una oración base sobre recta numérica. Usa un sujeto y un verbo.
2. Sentence Expansion because · but · so
Kernel: Number line matters in mathRecta numérica importa en matemáticas
Expand the kernel three ways. Add a reason, a contrast, and a result.
Number line matters in math because ___.Recta numérica importa en matemáticas porque ___.
Number line matters in math, but ___.Recta numérica importa en matemáticas, pero ___.
Number line matters in math, so ___.Recta numérica importa en matemáticas, entonces ___.
3. Sentence Types 4 ways to write a math idea
Tell one true fact about number line.Di un hecho verdadero sobre number line.
Number line ___.
Ask a question about number line.Haz una pregunta sobre number line.
How does ___ ?¿Cómo ___ ?
Show excitement about number line.Muestra entusiasmo sobre number line.
Wow, ___ !¡Guau, ___ !
Tell a partner what to do with number line.Dile a un compañero qué hacer con number line.
First, ___ .Primero, ___ .
4. Explain Your Reasoning use a sentence starter
I used a ___ circle because ___.Usé un círculo ___ porque ___.
The arrow points ___ because ___.La flecha apunta ___ porque ___.
This shows a limit like ___.Esto muestra un límite como ___.
Try It
Solve on your own. Check the answer key when you are done.
1. Which graph represents x ≤ 10?
- Closed circle at 10, shaded left
- Open circle at 10, shaded left
- Closed circle at 10, shaded right
- Open circle at 10, shaded right
2. A number line shows a closed circle at 8 and is shaded to the left. Which inequality does this represent?
- x ≤ 8
- x < 8
- x ≥ 8
- x > 8
Stretch Your Thinking Level 2 enrichment
Challenge task — explain your reasoning in full sentences.
A theme park has two rides. Ride A requires height h > 48 inches. Ride B requires height h ≥ 48 inches. A child is exactly 48 inches tall. Which ride can they go on? Explain using number line graphs for both inequalities.
Sentence starter: For Ride A (h > 48), the graph has a ___ circle at 48. Since 48 > 48 is ___, the child ___ ride A. For Ride B (h ≥ 48), the graph has a ___ circle at 48. Since 48 ≥ 48 is ___, the child ___ ride B.
Reflect — Exit Ticket
How would you graph the inequality x ≥ 9?
- Closed circle at 9, shaded right
- Open circle at 9, shaded right
- Closed circle at 9, shaded left
- Open circle at 9, shaded left
Answer Key & Teacher Guide
- Try It 1: A. Closed circle at 10, shaded left — x ≤ 10 means 10 IS included (closed circle) and values less than or equal to 10 are shaded (left).
- Try It 2: A. x ≤ 8 — Closed circle means the value is included (≤ or ≥). Shaded left means less than or equal to: x ≤ 8.
- Exit Ticket: A. Closed circle at 9, shaded right — x ≥ 9 means 9 is included (closed circle) and values are 9 or greater (shaded right).
Writing (TWR) — what to look for
- Kernel sentence: A complete sentence needs a subject and a verb. Example: Number line is a line with numbers in order. You use it to show answers.
- Expansion: because gives a reason, but shows a contrast or exception, so shows a result. Answers vary; each must keep the kernel idea and add the correct kind of detail.
- Sentence types: Statement ends with a period, question with "?", exclamation with "!", and a command starts with an action verb (a "bossy" verb).