We are testing other tasks, this is an example (every letters has a random *value and the user has to insert the total sum of the 3 given words):

http://www.diracoin.org/brainmathwords/brainmathwords0.png

This should be easy enough to make useless even a calculator and long enough to make the time to manually copy and paste every letter and its value to a spreadsheet bigger than calculate it by mind (or with the help of a paper).

As always, every feeback will be evaluated.


* in this example it is in a range 1-12 but we could decrease it 1-8 or less.