These are problems that are require some kind of observation. Students must decide what can be determined from a measurement and what has to be estimated or located in other resources.
Some examples of activities from the classroom:
1. What is the thickness of a single page from your text? (No measuring tools are allowed.) Use this result to find the diameter of a single period at the end of a sentence in the book.
2. When you quickly pull a piece of scotch tape off the table, it wraps itself around your arm because of static electricity. Estimate the number of excess charges on the tape.
3. What should be the spacing of the top two frets on a guitar?
4. Find the coefficient of kinetic frictionbetween your book and the table.