summer math

In today's letters to the editor, Melinda Mulcahy starts off by making an interesting point about the hours teachers put in beyond the contract day, so they shouldn't feel guilty about taking a long summer vacation. (She doesn't mention summer classes, prep time for a new curriculum, or second jobs to pay the bills.)

But then, in the middle of her missive, something goes wrong.

A teacher in my building works an average of 10 hours per week beyond her contracted time in order to do the job well. Often, even more is required.

So I multiplied 10 hours by 36 weeks per school year, then divided by 5 days per week and divided by 7.5 hours per day and was shocked by my result.

I found that this teacher actually works 9.6 WEEKS per school year without pay.

In my case, I can then divide the result by 0.6, since I am a part-time teacher, and my overtime computes to 16 weeks per school year.

Not much wrong with the first calculation. If we were all technical about off-duty lunch, the number of weeks would only shoot up to ten and some change.

But then Mulcahy makes the assumption that a .6 teacher works ten hours per week beyond the contract, which, speaking as a one-time .6 teacher, isn't a practical assumption. Factoring that in, we get six hours by 36 weeks divided by 5 days at 4.5 hours per day, and, lo and behold, Mulcahy works 9.6 weeks without pay.

(Even if Mulcahy's assumption is right, and a .6 teacher really does work as much beyond the contract as a full-time teacher, the move to divide by .6 and claim to work 16 weeks extra is only going to confuse readers, who will forget that those 16 weeks are composed of 4.5-hour days--and thus the same number of total hours, 360, as the full-time teacher's.)

As teacher advocates, our hearts have to be in the right place--but so do our decimals.