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My husband and I cannot figure out this mathematical riddle, to save our lives, despite him being a math teacher. The riddle is as follows:










Your help would be greatly appreciated.


marked as duplicate by DooplissForce, greenturtle3141, Kate Gregory, Deusovi May 28 '17 at 2:48

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  • $\begingroup$ @DennisMeng In the riddle, how is the number "4" written? Does it appear as if on a digital clock, or does it have the enclosed "triangle" space? $\endgroup$ – MikeQ May 27 '17 at 23:57
  • $\begingroup$ If it is the same, the 4 would break it. It could be phrased differently... $\endgroup$ – ben-Nabiy Derush May 28 '17 at 0:15

The answer to this may be tricky to explain due to font issues, but it would make sense if written out with a stick figure 4 (open) rather than the typical font 4 (closed).

In every instance, it is the

number of holes or circular like openings in the number.

For the first example:

$8 = 2$, $8 = 2$, $9 = 1$, $8 = 2$ for a total of 7

So the final answer would be:

$4500 = 2$

  • $\begingroup$ No problem. Even if it was a duplicate, I figured an answer would not hurt (as the other indicates the 4 as counting) $\endgroup$ – ben-Nabiy Derush May 28 '17 at 2:49

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