What's going on

• Measure how you can concentrate.
• ... and how the time of day, fatigue, music, rumble
affect it
• Nothing intellectual, just mark all nines in the number matrix.
• You can tag or untag.
• If you make a mistake, you can find the error and resubmit (but you'll get as many seconds as the size: 5, 15, 25).
• There are three job sizes to choose from.
• You don't have to register or log in, the login is just to mark your results.

Results