Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE checking ( custid number, balance number )
TABLE: CREATE TABLE savings ( custid number, balance number )
TABLE: CREATE TABLE accounts ( custid number, name text )

### Question ###
What is the average balance in checking accounts?

### Accurate SQL ###

SELECT AVG(balance) FROM checking