Misc: what ancient measure is the distance from the elbow to the tip of the middle finger?

Questions

This cereal's box features an empty bowl and the phrase "more, please."?

This cereal's commercials feature a "Cookie Crook" and a "Cookie Cop"?

A big whang of a novel by Julie Edwards. (AKA Julie Andrews)?

Difficult detective stories for children, but excellent?

Judy Blume's first childrens' best seller?