For the Wii, it is blocks displayed divided by eight equals Megabytes (128kb per block then). For the Gamecube, first, Nintendo only advertises them in Megabits, so you'll need to divide that by if you want to know their equivalent Megabytes. Second, each block on a GC memory card is 8kb. So, an advertised 128Mb card is 16 megabytes, or 2048 blocks. Your 64kb is kilobits, so you just needed to divide by eight one more time to get kilobytes.