problem in installing the cuda 8

i have downloaded cuda toolkit 8, by checking all per-installing requirement, on ubuntu linux 16.04 64 bit by using deb(local) type installer type. i was suggested to .do the checksum for downloaded file . i got following
$ md5sum cuda-repo-ubuntu
md5sum: cuda-repo-ubuntu: No such file or directory

and i also followed the installation command .
i got answer cuda file not found .
you are requested to help me how to install the cuda 8 on laptop having graphics card of NVIDIA GEFORCE.
thank you