Lesson 4 – Making predictions and changing variables using your spreadsheet Goals: Make predictions about what will happen if you change variables. Change variables in a spreadsheet to see what effect they have on the rest of the data. Identify and solve a problem within a spreadsheet.

Starter (5 Minutes) Find the keywords in the word search for this unit.

Task 1 – Changing variables in your spreadsheet (10 Minutes) Reduce the selling price of your CDs by 20pence each. What do you predict (think) will happen? What effect has reducing the selling price had on the profit made on each CD?

Task 2 – Creating a graph to show the new data (15 Minutes) Create another graph to display the new data showing the artist name and the profit made on each CD. Save it with a new name e.g. ‘Spreadsheet changed’, highlight the graph, put a header on it with your name and print it out. Annotate to explain what it now shows and what has happened.

Now that you have reduced the selling price of each CD how many CDs do you have to sell (have in stock) to make the same amount of money (profit) as when they were more expensive? (The amount of profit when they were expensive is recorded above) How to do this…… Look at your changed spreadsheet where you reduced the price of all the CDs and change the amount of stock on the shelf for each CD until you reach roughly the same amount of profit. You now know how many CDs you need to sell to gain the same profit as when they were more expensive. Print out your spreadsheet with a title to show how many CDs you need to have in stock to make the same amount of profit. Task 3 – Identifying a problem and solving it (20 Minutes)

Record the Total profit on your sheet under Task 3. Reduce selling price of CD’s by 20 pence each. Produce a graph to show new data (artist name and profit made on each CD) Save the spreadsheet with a new name. Change the variable (amount of CD’s on the shelf) to gain roughly the same profit before you reduced the selling price by 20 pence. Print out spreadsheet after setting the page to Landscape (File, Page setup, landscape) and annotate it to explain what you did.