Okla. Stat. tit. 70, § 70-18-111: Average daily membership - Legally resident pupils

No pupil shall be counted in the average daily membership of any

district for the purpose set out in this article unless said pupil

is a legal resident of said district as provided for in Section 1-

113 of this title or has been transferred to said district. A pupil

moving from a school district during a school term shall be entitled

to attend such school for the remainder of that school term. School

districts shall not include out-of-state pupils in their average

daily membership for the purpose set out in this article. The

following pupils shall not be counted: Those who have attained

twenty-one (21) years of age by September 1 of that school year, or

who have completed the twelfth grade, except as elsewhere provided

for by law for veterans of World War II, the Korean War, or the

Vietnam Conflict, and those who have not attained four (4) years of

age by September 1 of that school year. In determining the ages of

pupils for State Aid purposes, birth certificates shall be

presented, if obtainable, as proof of age. Underage pupils in

kindergarten and first grade who have been in legal school

attendance in a public or private school in another state or in a

Department of Defense School for military dependents may be legally

enrolled and attend an Oklahoma school.