6.AT.9
Lesson 8-5-part2
Apply Day · Practice
MASTERY CHECK
☐ Exceeds☐ Meets Target☐ Needs Practice
8.5 · Part II
Application Practice for Today's Problem
Graph Inequalities · Number line
■ CONCEPT SUMMARY & GUIDED NOTES: 8.5 · Part II
1Graphing Inequalities on the Number Line
2Strategy Model — step by step
- Draw the boundary circle at the given constant number
- Open Circle (○) for < or > (boundary value is not included in solution set)
- Closed Circle (●) for ≤ or ≥ (boundary value is included). Shade right for >, left for <
3Mathematical Word Bank
- Graph Inequalities (Representar desigualdades en una recta numérica) — Show every solution to an inequality on a number line with a boundary point and an arrow.
- Number line (Recta numérica) — A straight line where numbers are placed in order; numbers get smaller to the left and larger to the right.
- Open circle (Círculo abierto) — An empty circle showing a number is NOT included.
- Closed circle (Círculo cerrado) — A filled-in circle showing a number IS included.
- Solution set (Conjunto solución) — All the numbers that make the inequality true.
- Inequality (Desigualdad) — A math sentence that compares two sides with <, >, ≤, or ≥.
4Watch out
- A common mistake in Graph Inequalities is treating ≥ and ≤ the same as > and < and drawing the wrong circle. For example, students often graph x ≥ 6 with an OPEN circle (as if it were x > 6), which wrongly excludes 6 even though 6 itself makes x ≥ 6 true. A second common mistake is choosing the right circle but shading the wrong direction — for x < 9 students sometimes shade right instead of left. Always check the symbol twice: once for the circle (does it have an 'or equal to' line?) and once for the shading direction (does the symbol point toward larger or smaller numbers?).
SECTION 1
REAL-WORLD CONTEXTS & PROBLEM SOLVING
[Applications]
-
1 MULTIPLE CHOICE
Which graph represents x ≤ 10?
- AClosed circle at 10, shaded left
- BOpen circle at 10, shaded left
- CClosed circle at 10, shaded right
- DOpen circle at 10, shaded right
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
A number line shows a closed circle at 8 and is shaded to the left. Which inequality does this represent?
- Ax ≤ 8
- Bx < 8
- Cx ≥ 8
- Dx > 8
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
Clue: the witness ran more than 15 feet, so d > 15. On the number line, what do you draw?
- AOpen circle at 15, shade right
- BClosed circle at 15, shade right
- COpen circle at 15, shade left
- DClosed circle at 15, shade left
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
Clue: the getaway car held at most 4 suspects, so s ≤ 4. How is this graphed?
- AClosed circle at 4, shade left
- BOpen circle at 4, shade left
- CClosed circle at 4, shade right
- DOpen circle at 4, shade right
✏️ Workspace & Solution Steps
SECTION 2
MATHEMATICAL WRITING & ERROR ANALYSIS
[Reasoning & Critique]
-
5 OPEN RESPONSE
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.✏️ Mathematical Justification & Response
📐 CER MATHEMATICAL PROOF MATRIX (CER 2.0)
SMP.3 / Proof & Justification
Writing Task: Justify why your mathematical solution is accurate and complete.
C Claim
Starter: My mathematical claim is that the solution is...
E Evidence
Starter: The evidence from the model/table demonstrates that...
R Reasoning
Starter: This proves my answer because the standard mathematical definition of...