Cutting a mango can be difficult due to its very thick pit, firmly attached to the pulp.
The easiest way to do it is first to remove its skin with a potato peeler. Once you're finished, just cut the fruit into three portions: the central portion must contain the whole pit. At this point, the two pit-free ends can be cut as you wish. Don't waste even a bit of your mango: cut the rest of the pulp around the pit from the central portion.