We all have our days... (open)

The blackboard had never looked so large or intimidating before.
It seemed to stretch for miles on either side as Sam stood staring
with peculiar intensity at the math problem written out in neat,
white chalk numbers. It stared back at her, the numerals turning
into evil little men that wagged their tongues in mockery. She
nibbled at her lower lip and twisted the bit of chalk between her
fingers, but still the solution evaded her. Frankly, the meaning of
the equation evaded her as well. She was miserable at her sums,
and the teacher knew it. Sam was sure that he had dragged her
up here as a particularly cruel form of torture.

A muffled snicker sounded out behind her, drawing her back up
straight with temper. Tossing her head, glossy braids snapping
sharply before settling into place along her spine, she mulishly
began writing numbers. They made no sense, and Sam knew
that there was no hope of stumbling across the correct answer,
but she couldn't bare to stand there dumbly. The laughter behind
her back returned louder, more of a guffaw this time. She heard
the teacher shushing the miscreant, but when she turned around
and revealed her woefully poor attempt at solving the equation,
the student cackled once again.

She was already in a foul mood this morning. Her mother had
caught her just as she was headed out for a morning swim before
school. Shocked at the near jungle state of her daughter's hair,
she forced Sam to sit motionless for a good thirty minutes while it
was painstakingly untangled one knot at a time. The captivity
grated on Sam's nerves, and by the time her curls were tamed
into tidy plaits, she was close to spitting nails. She was just
itching for a fight, and this anonymous person had just given a
perfect excuse.

Unable to control her temper this time, Sam snatched up the
chalk eraser and pitched it with all her strength at the culprit!