I used the USA square miles spreadsheet for this week. I used a formula to create the average number of people per square mile for 30 states. I add an equal sign for the box I want the number to appear in.I then click on the first box where a letter and a number show up, then I add the operation and click on the other box for the other formula and the answer will appear in the box you select. Spreadsheets are useful for things that have long lists of items or numbers such as presidential elections or baseball home runs.