It makes them easier to be drinken, but milkshakes can also be consumed without straws on their own, or with spoons, too.
I need 100 straws.
8 straws.
Milkshake straws are larger in diameter than soft drink straws. Since milkshakes are thick, they are very hard to drink with a small straw, thus the increased diameter of the straw makes it easier to drink.
You'll need 18 straws because it has 18 edges
6
18 straws.
12
6
assuming the straws do not bend, you would need six
That's going to depend on what shape you're building, which, as far as I can see, you neglected to mention.
You would need 12 straws because a cuboid has 12 edges, 8 vertices and 6 faces
It means that you need teamwork to acclompish something. If you use only one of your straws you cant acclompish your goal. You must use other people's straws too.