kevin perz , 56 , a father-of-four and business owner , has been looking up the teachers he has the fondest memories of from his days at parkway central high school in chesterfield , missouri .
over the past few years he has been mailing them a ` gift ' .
started in 1992 , when he sent a check to his calculus teacher made out for $ 5,000 .
then in 2002 , he sent a $ 10,000 check to his former business teacher , a check for $ 10,000 .