I came across freerice.com through someone’s 101 in 1001 days list. I was immediately addicted.
From the FAQs:
How does the FreeRice vocabulary program work?
FreeRice has a custom database containing thousands of words at varying degrees of difficulty. There are words appropriate for people just learning English and words that will challenge the most scholarly professors. In between are thousands of words for students, business people, homemakers, doctors, truck drivers, retired people… everyone!
FreeRice automatically adjusts to your level of vocabulary. It starts by giving you words at different levels of difficulty and then, based on how you do, assigns you an approximate starting level. You then determine a more exact level for yourself as you play. When you get a word wrong, you go to an easier level. When you get three words in a row right, you go to a harder level. This one-to-three ratio is best for keeping you at the “outer fringe” of your vocabulary, where learning can take place.
There are 50 levels in all, but it is rare for people to get above level 48.
My best level is 44 but I can’t sustain it. I am bouncing between 40-44. I have donated 3280 grains of rice so far. If you are a word junkie, go try this.