Innumeracy rampant: Suppose average class size were 25

Innumeracy 2: If average class size were 25 students

Let’s suppose the Ontario Secondary Teachers took the Ford government at its word, and negotiated an average class size of 25 students. (1)

Given a high school of 1120 students (the number I used in Innumeracy 1).
Number of classes would be 1120/25, or 44.8, or 45 in round numbers. So we would need 45 teachers for those classes.

But in any one period, 1 in 5 teachers has a prep period (also used for “standby”, or emergency supervision). So we would need 45 x 1.25 = 56.25 teachers to cover a full timetable. We would also need a principal, a vice-principal, and three guidance counsellors. (2)

That comes to a total of 61.25 teaching staff. (The 0.25 teacher would be one hired to teach one class.)

That results in a student-teacher ratio of 1120/61.25, or 18.3:1. That’s well below the 22.5:1 that the Ford government decided to raise to 28:1. (3)

Footnotes

(1) In the past, school boards have resisted average class size numbers. They did the arithmetic, and understood what it actually meant.

(2) Some school boards would add a half-time vice-principal, which would bring the staffing total to 61.75, and a student teacher ratio of 18.2.

(3) Because some classes will be capped around 22 to 24 because of safety or limited facilities, the larger classes would be over 30.