How to know if iphone is using carrier instead of home Wi-Fi?

Hi, i jsut got my brand new iphone today, first time that i have those touch screen phones so its a big change. However i'm wondering if it is using my phone service wasting money, instead of my Wi-Fi, I have connected to the home Wi-Fi, but i want to amke sure that its using the Wi-Fi and not the 4G

How to Turn Off/check iPhone 5 4G LTE

Go to Settings on the iPhone 5 Home Screen.

iPhone 5 4G LTE Off
Settings on the iPhone 5.

Tap on General.

Turn Off 4G LTE on the iPhone 5
iPhone 5 Cellular Settings.

Tap on Cellular.

How to Turn Off 4G LTE on the iPhone 5
Turn 4G LTE off on the iPhone 5.

Toggle Enable LTE to Off.

To turn 4G LTE back on, simply toggle the switch to On.

This same menu offers control over what services user the iPhone data and the option to turn data completely off.
Full guide here with images -
http://www.gottabemobile.com/2012/09/21/how-to-turn-off-4g-lte-on-the-iphone-5/

The iPhone will always use wi-fi for practically everything as long as it is connected to a wi-fi hotspot, which is indicated by a wi-fi symbol on the status line at the top of the display. The only things that won't go through wi-fi are voice telephone calls via your normal cell number, and SMS texting, which also goes through the cell number.

If it doesn't have the Wi-Fi indicator then it's using the cellular network.

Actually everyone is correct! IT actually is that your iPhone is using it's core processor. It's using not only the 4G LTE data, but when your phone picks up a wireless connection it automatically will switch to Wireless Connection. However, when you on the highway for example, it will use your data because it can't pick up the following:

A Signal
Power Cable
Home Network
Network
Wi-Fi is off.

You can't turn your 4G LTE Off though. You would have to reset your whole phone which I don't think you want to do. However, you may choose to turn off Internet Connections. This will enable you to use your Celluar Data. However, keep in mind that when you use your data it costs money. The more you do, the more money you'll see at the monthly bill. Especially with iPhones, it's easier to use Wireless connection/ Internet Connections because really cellular data is used when you can't connect to a router. The main reason why you can't see the difference is because the 4G LTE system at the top of your iPhone next to the time to the left is the same as the Wi-Fi Symbol. However, you main difference is because when your out of the house and can't connect to the router you will know your using cellular data. When it says "can't connect" it will automatically switch to cellular data for you. However, when you get to your house, it will automatically connect to your wireless router. In fact, any house that your iPhone knows the IP Address for Internet to, will automatically connect to your phone. Hope this sort of helped.