Dynamically Scale an Equation in MathJax

 Long expressions can extend beyond their containers: $$\displaystyle\sum_{n=1}^{10} {1\over n} = {1\over 1} + {1\over 2} + {1\over 3} + {1\over 4} + {1\over 5} + {1\over 6} + {1\over 7} + {1\over 8} + {1\over 9} + {1\over 10}$$ You could turn on line-breaking to solve the problem, but may prefer not to. Instead, you can rescale the math after it has been typeset.