JEFFERSON CITY, Mo. -- State education officials have looked into 19 allegations of cheating and improper procedures on standardized tests given by schools this spring.

Missouri Department of Elementary and Secondary Education spokesman Jim Morris said Tuesday that the number of incidents is typical in a given year, and that only a few amounted to cheating by school officials, with test results tossed out. Most, he said, were a matter of not understanding the proper procedure, such as briefly allowing students to use a calculator on the test or not keeping test booklets locked up.

The 17 school districts, plus one charter school, investigated the problems and took action, and state officials reviewed what they did. Districts ranged from the St. Louis area to the Kansas City region to Branson.

In the Central School District in St. Francois County, the department said a high school teacher coached about 50 of 100 students to change their answers on a social studies test and allowed students to help each other. Those test results will be tossed, and the district is disciplining the teacher, the department said.

At St. Louis Charter Academies, the principal was fired and all test results were tossed after a teacher reported being told to help students with the tests, and teachers were reportedly told to return tests for students to complete unfinished sections, the agency said.

The state is still waiting to hear back on investigations of incidents involving St. Louis Public Schools and the Sheldon School District in western Missouri.