First Class requirement 3 is about knots. Scouts learn to tie a few different types of knots and then use the skill to make something useful.
3a. Discuss when you should and should not use lashings.
3b. Demonstrate tying the timber hitch and clove hitch.
3c. Demonstrate tying the square, shear, and diagonal lashings by joining two or more poles or staves together
3d. Use lashings to make a useful camp gadget or structure
Helps for this requirement are listed below.