I need 100 straws.
8 straws.
18 straws.
You'll need 18 straws because it has 18 edges
12
8
10
6 of them
six, you need six
You would need 12 straws because a cuboid has 12 edges, 8 vertices and 6 faces
8
You would need 12 straws of equal sizes because a cube has 12 equal edges, 8 vertices and 6 faces