I found this one
$$\frac{(12+144+20)+\left(3 \cdot \sqrt{4}\right)}{7}+(5 \cdot 11)=9^2+0.$$
Which is :
A dozen, a gross, and a score
Plus three times the square root of four
Divided by seven
Plus five times eleven
Is nine squared and not a bit more.
I think this is very entertaining, thus I wonder if there is any similar limerick/math poem.
$$\int_1^{\sqrt[3]{3}} t^2\mathrm{d}t\cdot\cos\left(\frac{3\pi}{9}\right)=\ln(\sqrt[3]{e})$$ $$\text{Integral t squared dt,}$$ $$\text{from 1 to the cube root of $3$,}$$ $$\text{times the cosine,}$$ $$\text{of three pi over $9$,}$$ $$\text{equals log of the cube root of $e$.}$$
You can find some more here: http://www.trottermath.net/humor/limricks.html