freerice.com

Our school promoted this site and I would recommend it.
below are the subjects on the site.
ART

Famous Paintings

CHEMISTRY
Chemical Symbols (Basic)

Chemical Symbols (Full List)

ENGLISH
English Grammar

English Vocabulary

GEOGRAPHY
Identify Countries on the Map

World Capitals
LANGUAGE LEARNING
French

German

Italian

Spanish

MATH
Basic Math (Pre-Algebra)

Multiplication Table