When added to myself, I double in value. When multiplied by myself, I remain completely unchanged. What non-zero number am I?
1
1 + 1 = 2 (double 1), and 1 x 1 = 1 (unchanged).
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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