Evaluate $\lfloor6.7\rfloor+\lfloor-6.7\rfloor$.
I recognize that $\lfloor x\rfloor$ is the greatest integer function, which rounds down any real number to the nearest integer. For example, $\lfloor 3.2\rfloor=3$ and $\lfloor -4.6\rfloor=-5$. So, to evaluate $\lfloor6.7\rfloor+\lfloor-6.7\rfloor$, I just need to round down both terms and add them. Rounding down 6.7 gives me 6, and rounding down -6.7 gives me -7. Adding 6 and -7 gives me -1. 