whats a consecutive side and whats a consecutive angle?

Answer 1

http://www.mathsisfun.com/geometry/consecutive-interior-angles.html

For consecutive sides of a polygon, it is any two sides which connect with a single point.

Answer 2

Can you explain what the difference between rounding and front end estimation is? For example round 8267-2761= and front end estimate 6489-1807= . I a