intro_to_methods_practice.md

Practice Writing and Invoking Methods

1. Define a method, sings_fav_lyric that takes a lyric as input and print that lyric to the console as if it's been screamed (think all caps and a bunch of exclamation points)
2. Call your new sings_fav_lyric method, passing your favorite lyric as input.
3. Define a method, calculate_volume that takes three inputs: length, width, and height, and returns the calculated volume.
4. Call this method with values of your choosing and save the output to a variable called volume.
5. Define a method, calculate_tip which takes a single input called meal_value and returns a value equal to 20% of any given meal value.
6. Call this method with a value of your choosing and save the output to a variable called tip.
7. Write another method calculate_custom_tip that takes two arguments: meal_value and tip_percentage. Define this method such that when calculate_custom_tip(10.00, 20) is entered into the console, it returns the string "You should tip your server 2 dollars".
8. Invoke your calculate_custom_tip with the values above and save the output to a variable called custom_tip_amount
9. Invoke this method again and again with different values, saving the output to new variables.