Jessie has $4$ different tops and $5$ different bottoms. She wants to pick $1$ top and $1$ bottom to wear for her first day of school. How many different combinations of clothes are available for her to wear?     Jessie used her math knowledge to help her count the number of combinations.  $4+5$ = $9$  She declared that there are $9$ different combinations.     Is Jessie correct? If not, circle out her error and find the correct number of combination of clothes available. 
Overseas Competition->Knowledge Point->Counting Modules->Questions Involving Enumeration