If I Could Buy Anything- Math is Everywhere
- Author:
- jaronovitz, GeoGebra Materials Team
- Topic:
- Mathematics
Unit Price and Constant of Proportionality
Explore how unit price and constant of proportionality are related and how they can be represented using a table, a graph, an equation, and a verbal description.
Think of something that you enjoy and would like to buy the next time you go to the store. For purposes of this activity, keep the price under $10. Use the purple slider to set your unit price.
Use the slider scale to set the unit price. Round to the nearest whole dollar.
Representing a Proportional Relationship Using a Table
Describe the table- do you notice a pattern? How does buying 1 more unit (x) impact the cost?
Finding the Constant of Proportionality from a Table
Divide each cost (y) by the quantity (it's related x). What do you notice?
Is there a point on the graph that when extended the line would always cross?
Representing a Proportional Relationship Using a Graph
Desctibe the shape of the graph.
The Origin
What is the cost when the quantity is zero?
Explain the Relationship.
In you own words how you would use the number of items you buy and the unit price to find the cost.
Finding the Unit Price from a Graph of a Proportional Relationship
How can you find the unit price (k=constant of proportionality) from the graph? Select all that apply.
Using Your Unit Price to Write the Rule. y=kx
Write an equation using your unit price to show the relationship between the quantity and cost.
Use what you know to make a prediction.
What would your total cost be if you were buying 20 items?
What's Your Word Problem?
Write your own word problem using the item you selected and it's unit price.