Name is related to Mathematics. Mathematics is related to Classroom. Classroom can be used for Teach. Train is a type of Teach. 
Worldwide is related to Web. Web is related to Part. 
Name <--RelatedTo--> Mathematics <--RelatedTo--> Classroom --UsedFor--> Teach <--IsA-- Train 
Worldwide <--RelatedTo--> Web <--RelatedTo--> Part 