Make sure your Numbers document is open. You should see the "Numbers" heading in the top-left corner of the Mac menu bar.

Click File. It's in the top-left area of your Mac's screen. Doing so will invoke a drop-down menu.

Select Export To. This option is near the middle of the File drop-down menu. Selecting it invokes a pop-out menu.

Click Excel. It's in the Export To pop-out menu.

Click Next. It's in the bottom-right corner of the "Export Your Spreadsheet" window.

Enter a name for your file. This is how your file will appear in both Numbers and Excel.

Select a save location. You'll do so by clicking a folder (e.g., "Desktop").

Click Export. It's in the bottom-right corner of the window. This will save your Numbers document as an Excel document. You can double-click the document on any computer with Excel installed to open it in Excel.

Open Numbers. This is the green app with white bars on it.

Select a document to open. You may first have to tap the "Back" button in the top-left corner of the screen if Numbers opens to an existing document.

Tap …. It's in the top-right corner of the screen.

Tap Export. This option is near the top of the screen.

Tap Excel. It's the lower-left option on this page.

Tap Mail. You'll see the mail icon, which resembles a white envelope on a light-blue background, in the top row of the pop-up menu that's at the bottom of the screen.

Enter your email address. This should go in the "To" field, which is at the top of the screen.

Tap Send. It's in the top-right corner of the screen. Doing so will send the Numbers document in .XLS format to your email inbox, from which you can download it to a computer that uses Excel.