Fred has a puzzle. The instruction sheet, which is separate from the equation,simply says: "Make this equation true. You may ONLY draw ONE, PERFECTLY straight line". The equation is all alone on a blank piece of paper and reads:


There are 4 acceptable answers. You must get all 4 for a correct answer.

  1. Cross out the equals sign

  2. Turn the first $+$ into a 4 giving $545+5=550$

  3. Turn the second $+$ into a 4 giving $5+545=550$

  4. Turn the equals sign into less than or equal to

  • $\begingroup$ BONUS there is a fourth acceptable answer. good on you! $\endgroup$ – Theodosius Von Richthofen Nov 12 '14 at 21:28
  • $\begingroup$ Joe K added the fourth answer but Michal answered all 3 first (when i said i needed 3 answers) $\endgroup$ – Theodosius Von Richthofen Nov 12 '14 at 21:33

I think the fourth answer, which hasn't been posted yet is:


That makes all of them:


  • $\begingroup$ I was supposed to give you a bounty, but it expired as I was not active due to personal reasons. I'll therefore upvote ten of your answers to give you 100 reputation ;) $\endgroup$ – Mr Pie Jan 11 at 7:06


negating the equality.

You could negate the entire statement, depending on how you interpret the equation...
5+5+5=550    could evaluate to "true" in some contexts... ^^

  • $\begingroup$ This almost feels like cheating ;-) $\endgroup$ – John Dvorak Nov 12 '14 at 21:25
  • $\begingroup$ @TheodosiusVonRichthofen umm... You didn't say that $\endgroup$ – John Dvorak Nov 12 '14 at 21:28
  • 1
    $\begingroup$ @TheodosiusVonRichthofen you said there were 3 acceptable answers, and I provided one. Alas, someone already beat me to the other two :p. $\endgroup$ – Chris Sprague Nov 12 '14 at 21:30

I'd put a line

on one of the plus signs, straight up.
The equation would read 545 + 5 = 550


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