Because they are always multiplying.
Geometrees and trigonometrees
Sin Pi
Gee I'm a tree!
Math teachers, because every student counts.
He took the rhombus
Calc-U-LATER
Calculust.
Calculust
Grow old!
A puppy eventually grows up and stops whining. Thanks to PuddinHead742 for this one.
He had swine flu
Does this smell like chloroform to you
A polynomeal
All the inequalities
They are all #2s.
Because they always work problems out with a pencil.
Because if they count one more it would be 2gross to continue.
He started counting then fell asleep.
Mine is hickey on a hemorrhoid.
Because asteroids was already taken.