If you don't know the meaning of a word, you can literally Google "{The word you don't know} definition." Google.com is a really handy and easily-accessed dictionary.
There is a trap in part 2, by the way, that can trip people who try to use maths:
Spoiler
The values are so large that if one uses single precision (32 bit) floating point values, the result will not be correct. Double precision floats yield the correct result.
This means, that doing integer calculations isn't as bad as it sounds at first.