Calculator in words

Write a method that takes math questions in English and solves them. For example, calculate('What is 5 plus 3?') should return 8.

Start simple, and work your way to more complex, implementing these behaviors:

Addition, e.g. "What is 5 plus 3?". Other arithmetic operators (subtraction, multiplication, and division). For division, don't forget about floats and integers! Powers, e.g. "What is 4 to the 3rd power?" Multiple operations, e.g. "What is 4 plus 6 divided by 2?" Multiple questions, e.g. "What is 2 plus 3? What is 7 divided by 4?" Finally, refactor your code to use regular expressions. Rubular is a great site to experiment with regular expressions in Ruby.