Hi Doris,
My Surface Pro 3 has exceptional battery life. Might be a good idea to check a couple of things:

1 - Reboot your machine every day. Sometimes software gets memory leaks or gets in a loop and eats processor cycles. A driver that's off the rails may prevent components of the machine from sleeping, and using excess power. Some people never or rarely reboot, but rebooting is the single best thing you can do for your machine. At the end of every day, before walking away from the machine for the day, the last thing I do is a reboot.

2 - Check your power settings, make sure it's set to Balanced. If it's on High Performance, it will suck the battery pretty fast.

3 - Make sure you're not running with the screen at full brightness all the time. Full brightness seriously impacts battery life.

4 - In "Balanced" mode, check your settings. I have my computer set to shut off the screen after 5 minutes, and sleep after 15. Your computer may be staying awake even after the screen shuts off.

5 - If you're not on Wifi, shut wifi off. Wifi eats battery as well. That said, I can go almost all day with Wifi on. Shutting Wifi off helps with battery life, but it's not a single cause of battery drain.

6 - If you have third party antivirus, disable your virus protection for a little while and see what that does to battery life. Some antivirus software never sleep and is always running full bore, even when you're not connected to anything. If that makes a big difference, see if there's settings changes that may reduce battery impact.

If all that doesn't help, there may be something wrong with your battery. Have it checked at a Microsoft store.