Chapter 4.3, Problem 14P

Carmen says that it’s easy to multiply even numbers by 5 because you just take half of the number and put a zero on the end. Write equations that incorporate Carmen’s method and that demonstrate why her method is valid. Use the case 5 22 for the sake of concreteness. Write your equations in the following form:

   $5.\text{ 2}2=\text{some expression}$

     $=\text{some expression}$

     $=:$

     $=110$