If you have 4 pencils and I ate 7 apples, how many pancakes will fit on the roof?
Purple, because aliens don't wear hats.
Is this the way how you see maths? Then you probably won't crack up while being told a maths joke. But are there really some funny ones? Even for non-mathematicians?
Yes they are - I've done the research for you - prepare to laugh =) (At least a bit.)

Unrivalled number one:
John has 32 candy bars. Then he eats 18 candy bars.
What does John have now?

Cavities. John has cavities.

This also a way how to explain what's maths:
Maths: the only place where people buy 60 watermelons and no one wonders why.

Another special maths problem:
Think of a number between 0 and 10. Add 32 to it. Multiply the sum by 2 and then subtract 1.
Now close your eyes.

It's dark, isn't it?

(Don't) try this with your teacher:
"Find x."
"Why? Do I look like a pirate searching for a hidden treasure?"

But if you're still fighting that bloody x, just make yourself clear:
Dear maths, I'm sick and tired of finding your "x". Just accept the fact that it's gone. Move on, dude.

Romans nailed that anyway thousands of years ago:
Romans didn't find algebra very challenging because x was always 10.

Still didn't find any of them funny? If not, I don't blame you, because 5 out of 4 people have a problem understanding jokes about maths =))
So forget x for a while and enjoy the rest of the day.