# A mathematic riddle [duplicate]

A mathematic riddle:

If $$1+9+8=1$$, what is $$2+8+9$$?

I know, many of you out-of-the-box-thinkers, I really like it,
but please don't give answers to this riddle as $$1=0$$ and $$9=0$$ and $$8=1$$, that's why $$1+9+8=1$$.

Good luck!

As it has been solved here is the link for the puzzle.

• This doesn't seem to be your riddle, looking it up online comes back with dozens of hits, so could you show where you found it? Aug 19, 2020 at 16:09
• Yes, but it has the answer with it. Aug 19, 2020 at 16:11
• For sources that provide the answer, mention that the puzzle is from elsewhere and then add the source once the puzzle is solved. See here Aug 19, 2020 at 16:13
• Just realised this is actually a duplicate on PSE - d'oh! See Number related puzzle. But not even close to math. What is it? Totally didn't spot that before I answered (and only thought to check at all because BG spotted it elsewhere on the web)...
– Stiv
Aug 19, 2020 at 16:14

2 + 8 + 9 is:

10

Because:

We need only look at the first letters of each number when spelled out as words:

One + Nine + Eight = ONE (1)

Thus:

Two + Eight + Nine = TEN (10)