To find out how much memory is available, go to Settings, click General and select "iPad storage." If you are close to one gigabyte remaining, you'll need to delete some data or apps.

Here's how:

On the same screen that shows how much memory is available, Apple lists the apps and suggests what you can delete to save space. You can also make your own decisions by clicking each app to see how much memory it's using, then choosing whether to delete or "offload" the app. (Offloading deletes an app but keeps its stored data in case you want to reinstall the app in the future. See tinyurl.com/5n6m35hb).

Another way to free up storage space is to copy some of your photos to a non-Apple online storage service, such as Dropbox or Microsoft OneDrive, then delete them from your iPad. Don't rely on Apple's iCloud online service; it will delete whatever the iPad does.

Crashing apps can also be caused by software problems.

Here are some potential fixes:

Restart the iPad. If it won't respond because of an app crash, you can "force restart" it (see tinyurl.com/ycb7judk).
Make sure you've installed the latest version of the iPad operating system. Go to Settings, click General and click "software update" to see if a newer version is available.
Update the apps on your iPad through the Apple App Store. If you have an older version of an app, it may not work well with recent upgrades of the iPad's operating system. After updating the apps, restart your iPad.
Try uninstalling and reinstalling apps you use frequently. That will fix problems caused by a flawed installation. Do this first with apps you installed about the time the problem started.
Try resetting your iPad. In addition to fixing some software problems, the reset will also erase settings for your Wi-Fi connection, location and privacy (see tinyurl.com/5avy77fh), but you can add them again. Follow these reset instructions carefully: Go to Settings, click General, then click "transfer or reset iPad." In the next menu, click "reset." (Do not click "erase all content and settings" because it will permanently delete all apps and data on the iPad.)

Q: In your column about fixing a disappearing Mac cursor (see tinyurl.com/2p875fpn), you suggested "force quitting" an app to find out if it interferes with the cursor. How can I do that if the cursor isn't visible?

CONNIE HILL, Colorado Springs

A: Even if you can't see the cursor, you can use your Mac's keyboard to force-quit an app.

Simultaneously hold down the "command," "option" and "Esc" keys on your keyboard. That will bring the force-quit menu to the screen. Use the arrow keys to select an app from the list, then push the key labeled "enter" or "return" to force-quit that app. In the resulting pop-up window, you'll be asked again if you want to force-quit the app. Click the "enter" or "return" key again.

E-mail tech questions to steve.j.alexander@gmail.com or write to Tech Q&A, 650 3rd Av. S., Suite #1300, Minneapolis, MN 55488. Include name, city and telephone number.