Algebraic phrases to expressions using increased by a number increased by 9

The video tutorial explains how to determine the correct mathematical operation to increase a number by 9. It discusses why addition is the appropriate choice over subtraction, multiplication, or division. The tutorial introduces the use of variables in algebra, using 'P' to represent an unknown number, and demonstrates how to express the increase as 'P + 9'.

What new insight or understanding did you gain from this video?