-- Homework 26, problem 3: Calculator object.
--
-- Build a `calc` table with:
--   calc.value         -- starts at 0
--   calc:add(n)        -- adds n
--   calc:sub(n)        -- subtracts n
--   calc:mul(n)        -- multiplies by n
--   calc:show()        -- prints "Value: <value>"
--
-- Chain a few calls and confirm the value updates.
--
-- Run with: lua exercises/26/homework/03-calculator.lua

-- Your code goes here: