Complex sentence: At 08:25am on Monday 30th March 2009,100 Students walked out of 1st period and went to the back of the school in demonstration of Vertical Tutor Grouping and went on later in the college day and caused the disruption of the lessons planned for the day.
Split into simpler sentences: At 08:25am on Monday 30th March 2009, around 100 Students walked out of 1st period and went to the back of the school in demonstration of Vertical Tutor Grouping. They went on later in the college day and caused the disruption of the lessons planned for the day.