Eclipse has some very nice tools to help you improve coding.
One of those things is line numbers. To get the line numbers in your Eclipse follow this tutorial.
When you have Eclipse open you need to hover your mouse above Window and click on Preferences.
This screen will open.
Select: General, Editors and click Text Editors. You should see this.
Click the show line numbers button and the line numbers appear after clicking apply and Ok.
The line numbers are pretty nice, but they can also be very useful as you will see in a future tutorial.