# 3. INEQUALITIES

“Good math = math you want to talk about.”

#### IN THE CLASSROOM

###### Ontario Curriculum
• Gr. 1/2
• B2.2 – addition facts up to 10/20
• Gr. 3-8
• C3.1 – solve problems and create computational representations of mathematical situations by writing and executing code
• Gr. 4-8
• C2.3/C2.4 – solve inequalities and verify and graph solutions
• Gr.5-8
• C3.2 – read and alter existing code, (including code that involves conditional statements and other control structures)
• Gr. 6-8
• C1.2 – linear growing patterns, constant rates & initial values
• Gr. 9
• C1.1 – research an algebraic concept to tell a story
• C4.2 graph relations represented as algebraic equations and their associated inequalities, and identify various characteristics and the points and/or regions defined by these equations and inequalities
• C2 – apply coding skills to represent mathematical concepts and relationships dynamically, and to solve problems, in algebra and across the other strands
• Gr. 10
• inequalities
###### Implementation
• Gr. 1-2
• Students find pairs of numbers whose sum is less than 10 (_+_<10).
• Gr. 3-9
• Students use masking tape and a string taped from the floor to the ceiling to represent 3D coordinates in the classroom.
• Students discuss the meaning of x > 3 in 1D, 2D and 3D.
• Gr. 3-10
• Students use Scratch code that plots an inequality in 2D, they solve puzzles where they edit the code to match other inequality plots.
• The complexity of the plots varies with grade level.

#### 3A. INEQUALITIES in 1D, 2D & 3D

Using masking tape, divide the classroom floor using x and y axes, and add a scale to each axis, from -5 to 5. Then, tape a string vertically, from where the x/y axes meet to the ceiling.

Q1. If you live on the x-axis (in 1D), where is x > 3?

Q2. If you live on the x-y plane (in 2D), where is x > 3?

Q3. If you live on the x-axis (in 3D), where is x > 3?

#### 3B. PUZZLE 1

Q4. Run the code below at https://scratch.mit.edu/projects/540216861/editor

• What does the code do?
• How does it do it?

Q5. Edit the code to get the following inequality graphs.

#### 3C. PUZZLE 2

Q6. Run the code below at https://scratch.mit.edu/projects/540229313/editor

• What does the code do?
• How does it do it?

Q7. Alter the code as shown below.

• Predict how the output will change.
• Run the code to test your prediction.
• Explain the result.

A.

B.

Q8. Alter the code to get the output shown below.

Q9. Alter the code as shown below. [Notice that AND changed to OR]

• Predict how the output will change.
• Run the code to test your prediction.
• Explain the result.

#### 3D. PUZZLE 3

Q10. Run the code below at https://scratch.mit.edu/projects/1059421111/editor

• What does the code do?
• How does it do it?

Q11. Edit the code to get each of the following.

#### 3E. PUZZLE 4

Q12. Run the code below at https://scratch.mit.edu/projects/540225499/editor

• What does the code do?
• How does it do it?

Q13. Alter the code as shown below.

• Predict how the output will change.
• Run the code to test your prediction.
• Explain the result.

Q14. Alter the code as shown below.

• Predict how the output will change.
• Run the code to test your prediction.
• Explain the result.

Q15. Alter the code as shown below.

• Explain the result.
• Predict how the output will change.
• Run the code to test your prediction.