Does a straw have 1 or 2 holes?

Okay I could be wrong but I think a hollow cylinder (the paper towel roll) is homeomorphic to a torus which has one hole, therefore the role of paper towels has 1 hole with 2 openings. read more

Since cutting a straw into a really short piece won’t create or destroy any holes, it’s obvious that the number of holes in the paper ring you cut (1) is the same as the number of holes in the straw you cut (1) and the same as the number of holes in the entire straw, 1. read more

On that basis, it makes sense to claim a straw has one hole. Think of it like a donut: it only has one hole. Just because the hole in the straw is longer, that doesn’t mean it counts as two hole. read more