Elapsed time – for 4th & 5th grade on Hard, or earlier grades on easy
http://www.shodor.org/interactivate/activities/clock3/index.html

Fun Brain change maker – Choose level, and country of currency
http://www.funbrain.com/cashreg/index.html

Very challenging change game
http://www.apples4theteacher.com/change-game.html

NLVM – click on converting Units
http://nlvm.usu.edu/en/nav/category_g_2_t_4.html

Math Cats number conversion
http://www.mathcats.com/explore/convert.html

All conversion units
http://www.sciencemadesimple.com/conversions.html

PBS Kids Cyberchase has changed. This link will lead you to all their games. Your teacher will direct you which one to click on. 

http://pbskids.org/cyberchase/math-games/