Math Quiz Brain Game

Your goal is to make simple yet entertaining calculations as fast as you can. You will be displayed an integer and an mathematical operation to perform.
It involves basic mathematical operations (addition, subtraction, multiplication, division, exponentiation) that are sometimes combined to make the game a little bit more tricky and really great for training your brain and keeping it sharp.
For example: you are given the number 4 as a starting number and the operation that you need to perform is "square and add 3". You should square the number 4 and add 3 to the result. The correct answer is 19, then you will be given new operation such as "subtract 4 and multiply by 5". First you have to subtract 4 from 19 and the result will be 15, then multiply it by 5 which makes 75 and so on.