Mass and volume are not the same. You can stretch or compact an object to change its volume, but the amount of matter inside it will stay the same. In...
To add two numbers in a programming language, you just use a "+" between them. In Python (a programming language), it would look like: x = 10, y = 13;...
There are many ways to improve your times, one of which is improving your method. If you use beginner's method, it is important to learn CFOP or another speed-cubing method....
You need to practice solving it, then get faster and faster at it. You'll be a good cuber in no time only if you practice often, there is no shortcut...