CHICAGO (CBS) — Pink slips were landing in the mailboxes of teachers and non-union staff members in Elgin School District U-46 on Tuesday.

The school board has approved layoffs of 263 teachers, although most of them likely will be recalled next school year. More than 200 non-union support personnel also were receiving layoff notices.

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By law, the district must notify teachers of layoffs at least 45 days before the end of the school year.

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According to the district, the teacher layoffs are based on approval ratings, and time of service.

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U-46 CEO Tony Sanders said the reductions were the result of declining enrollment, expansion of a dual language program, and changes in classroom staffing.