Is Mexico considered as part of North America

Yes, Mexico is a part of North America.

Check this one on World Atlas. North America consists of Canada,
Greenland, Mexico, the United States, all the countries of Central
America and the island countries and dependencies of the Caribbean.
http://www.worldatlas.com/webimage/countrys/na.htm

This page has a list with all the countries that North America
consists of.
http://geography.about.com/library/maps/blrnorthamerica.htm

Some suggested links to get more info about Mexico

This one gives a quick insight about Mexico
http://www.worldatlas.com/webimage/countrys/namerica/mx.htm

This one gives an overview about their economy, geography and many
other aspects
http://www.emulateme.com/mexico.htm

Search term used:

countries of North America

I hope this answers your question. Please ask for clarification if you
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Regards,
netcrazy