CREATE TABLE list (classroom VARCHAR)
CREATE TABLE teachers (classroom VARCHAR, firstname VARCHAR, lastname VARCHAR)

How many students does KAWA GORDON teaches?
SELECT COUNT(*) FROM list AS T1 JOIN teachers AS T2 ON T1.classroom = T2.classroom WHERE T2.firstname = "KAWA" AND T2.lastname = "GORDON"
SELECT COUNT(*) FROM "list" AS "T1" JOIN "teachers" AS "T2" ON "GORDON" = "T2"."lastname" AND "KAWA" = "T2"."firstname" AND "T1"."classroom" = "T2"."classroom"