Units

It was mentioned in the classroom, but given the trouble I can see it has caused you, I would insist on the units we will use. You can have a look at the wikipedia kilobyte entry.

Unless we explicitly use the terms kiB, MiB or GiB or kibit, Mibit or Gibit we always imply units to be powers of 10. So:

1 kByte = 1000 bytes  ( = 8000 bits )
1 MByte = 1000.000 bytes
1 GByte = 10^9 bytes

and

1 kbit = 1000 bits
1 Mbit = 10^6 bits
1 Gbit = 10^9 bits.

Same applies when we mention data rates (bps or Bytes/sec) and file sizes (kB, MB, GB).

Please note that all this is the industry standard too.

Only storage space used to used powers of two as units.