Many of the tasks include pre-programmed spreadsheets for the hard calculations. Click the link to download. Each tab is labeled a – z. When you’re working in a spreadsheet it resides locally on your computer. Either save it and store it on your computer or upload it back to your project for future access.
See how to upload it to your project here.
If you break a formula in a spreadsheet, simply download a fresh copy for the link in the task.