6.AT.9
Lesson 8-5-part2
Apply Day · Set B
MASTERY CHECK
☐ Exceeds☐ Meets Target☐ Needs Practice
8.5 · Part II
Second Practice Form · Independent Application and Spiral Review
Graph Inequalities · Number line
■ ADVANCED CONCEPT ANCHOR: 8.5 · Part II
1Graphing Inequalities on the Number Line
2The Structural Procedure
- 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?).
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1 MULTIPLE CHOICE
A number line shows an open circle at 7, and the shading covers the numbers to the right of 7. Which inequality does this graph represent?
- Ax > 7
- Bx ≥ 7
- Cx < 7
- Dx ≤ 7
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
Which graph represents x < 5?
- AOpen circle at 5, shaded left
- BClosed circle at 5, shaded left
- COpen circle at 5, shaded right
- DClosed circle at 5, shaded right
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
Which graph represents x ≥ 3?
- AClosed circle at 3, shaded right
- BOpen circle at 3, shaded right
- CClosed circle at 3, shaded left
- DOpen circle at 3, shaded left
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
Which graph represents x > 8?
- AOpen circle at 8, shaded right
- BClosed circle at 8, shaded right
- COpen circle at 8, shaded left
- DClosed circle at 8, shaded left
✏️ Workspace & Solution Steps
📐 CER MATHEMATICAL PROOF MATRIX (CER 2.0)
SMP.3 / Proof & Justification
Writing Task: Justify why your mathematical solution is accurate and complete.
C Claim
State your direct mathematical answer/claim with units.
E Evidence
Cite exact numbers, calculations, dimensions, or graph data.
R Reasoning
Explain the mathematical theorem, property, or definition connecting evidence to claim.