Question: How to dice a potato quickly.
Options:
Slice the top and bottom off of the potato so it can stand upright. While the potato is standing cut it into slices. Take one slice at a time and cut it in to smaller slices.  Take each slice individually and cube it.
Cut the potato in half and then into slices 1/4" or less. Take half of those slices and slice them the other way so they look like fries. Then chop the fries so that they become cubes.
Answer: Cut the potato in half and then into slices 1/4" or less. Take half of those slices and slice them the other way so they look like fries. Then chop the fries so that they become cubes.