In this module students learn the properties of linear functions. They look at data sets, graphs of coordinates, and algebraic representations of functions. Then students go on a field trip to the US Mint to see how money is printed. From this they develop linear function models for calculating the number of bills printed, along with their dollar value.

Students begin by analyzing linear function data by identifying the common difference. The goal is to see the relationship among the common difference and the slope of the linear function.

Students use the Desmos graphing calculator to explore graphs of data and equations. Both types of linear functions are explored:

• y = ax
• y = mx + b

Students then watch a video about the US mint and how currency is created. Students use the information in the video to develop two linear function models: one for calculating the number of bills produced for every sheet of printed bills, plus another for calculating the dollar value of the printed bills.

Note: Be sure students are familiar with the concept of slope and the basic definition of a function.

In this module students apply their knowledge of linear functions to the context of distance vs. time graphs. They look at data sets, graphs of coordinates, and algebraic representations of distance vs. time functions. Then students go on a field trip to a Nascar race to see how timing at the pit stop has an impact on distance vs. time data.

Students begin by analyzing linear function data by identifying the common difference. The goal is to see the relationship among the common difference and the slope of the linear function.

Students use the Desmos graphing calculator to explore graphs of data and equations. Both types of linear functions are explored:

• y = ax
• y = mx + b

The goal here is to connect the slope of the distance vs. time graph to the speed of the car. Students then explore the graphs of cars with different speeds and initial distances.

Students then watch a video about Nascar pit crews and learn about the rapid-response pit crews who change the tires on the race cars and how the timing of this affects the distance vs. time graph of the cars. Students use the information in the video to analyze linear function models for different pit crew times.

Note: Be sure students are familiar with the concept of slope and the basic definition of a linear function.

Throughout the lesson various assessment items are included, which are then scored. A teacher's guide includes a detailed description of all components of this lesson.

This lesson addresses the Grade 8 Common Core Standards but it can also be used in grades 9 and 10 for review purposes.

This lesson can be assigned to individual students or teams of students. The lesson can be completed in about 20 to 25 minutes. 

Crickets are known for their chirping sounds. But did you know that the number of times a cricket chirps per minute is an indicator of the outside temperature? In fact, the relationship between cricket chirps and the outside temperature can be modeled by a linear function. In this module, students will explore the function that can be used to determine the outside temperature based on the number of times a cricket chirps per minute.

First, students watch a video that describes the chirp-temperature phenomenon. Students are then walked through the process of developing the linear model. They look at inputs and outputs, determine the dependent and independent variables, and explore the linear function with a graphing calculator activity.

In this module, students explore a physics-based application of linear functions: Hooke's Law. By exploring the properties of springs, a simple linear model is developed. Students then explore applications of Hooke's Law, from weight scales to bungee cords.

Students investigate the properties of springs and identify two variables: the displacement of the spring (extension or compression) and the amount of force involved. From this students identify the independent variable and dependent variable. A graphing calculator activity (using the Desmos graphing tool) allows students to explore the value of k in the function F = kx.

When a rocket is launched into space, it starts from rest and within minutes reaches speeds of tens of thousands kilometers per hour. In other words, the rocket accelerates.

In this module, students apply their knowledge of linear functions to explore the speed vs. time function. In the process they learn about acceleration, as well as the properties of this linear function.

Students first explore the equation for calculating acceleration. Then they use that to develop the speed vs. time linear function. 

This module can be completed in about 20 minutes. Make sure that students understand the basics of linear functions in slope-intercept form.

Temperature is one of the most important measurements that we deal with on a daily basis. Weather, climate, food preparation, health, and other phenomena involve some type of temperature measure. The two most common units of temperature measure are Fahrenheit and Celsius.

There is a linear function that allows you to convert from one unit to another. In this module, you'll learn about this linear function. In fact, students will learn about this function and its inverse.

The module starts with an analysis of Celsius-to-Fahrenheit data. They look at the functional relationship between the variables and develop a linear model using the Desmos graphing calculator. They analyze the properties of this linear function and look at its graph.

Next, students analyze Fahrenheit-to-Celsius data. They also develop a linear function model using the Desmos graphing calculator.

Finally, they compare the graphs of the first function and its inverse to identify properties of functions and their inverses.

As the size of a circle changes, so does the size of the diameter and that of the circumference. In fact, there is a linear relationship between these two measures. This relationship can be modeled with a linear function. In this module students will study this linear function and examine its properties, including the fact that the slope of this function is π itself.

This is a hands-on module in which students will measure the diameters and circumferences of a number of different containers. This data gathering will lead to graphing the data. From that students develop a linear model using the Desmos graphing tool. Students will see that the relationship between circumference and diameter has to do with π. In fact, the slope of the linear function is π itself.

For the hands-on part of the lesson, make sure you have all the materials: Different size cylindrical containers (bottles, cups, etc.), string, marker, and a ruler (preferably a caliper). Collect all the student data and use the embedded Desmos graphing tool to graph the data and explore the linear function.

The module concludes with an overview video about the number π. 

What do drones have to do with domain and range? In this module, students learn about an emerging high-tech delivery system and use that as a vehicle for learning about a function's domain and range. Students will graph data from a table and explore domain and range, and then they graph a continuous function. This highly engaging module will give students a solid understanding of algebraic functions, specifically domain and range.

In this module students will learn the following concepts:

• Finding the domain and range for a set of coordinates that define a function
• Finding the domain and range of a continuous function that doesn’t extend to infinity
• Finding the domain and range of a continuous function that extends to infinity

In this presentation we show how to convert a linear equation in Standard Form to a linear function in Slope Intercept Form. We go over the reason for such a conversion and applications that give rise to these equations. Note: The download is a PPT.

Explore Fahrenheit-vs-Celsius graphs using this Desmos graphing calculator activity. In this activity explore linear functions of the form y = mx + b.

Explore Cost-vs-Time graphs using this Desmos graphing calculator activity. In this activity explore linear functions of the form y = mx.