A number appears — press ODD or EVEN as fast as you can. Tests automatic numerical categorization and processing speed.
Keyboard: O for Odd, E for Even
Very Easy
Numbers 1–10, no time limit.
Easy
Numbers 1–20, no time limit.
Medium
Numbers 1–50, 2 s per number.
Hard
Numbers 1–99, 1.5 s per number.
Expert
Numbers 1–999, 1.2 s per number.
Scientific Background
Based on: Parity Judgment & SNARC Effect (Dehaene et al., 1993; Hines, 1990) (Dehaene et al., 1993)