Questions

I heard one of my coworkers did this to his previous employer (e. g. took a fixture with him), and he tries to justify it by saying he never got a raise from previous employer. This is unethical to me.

The reason given for this policy is that you don't want to take the kid out of the game in the first quarter by giving a zero and creating a 30-week discipline & attendance problem. The local Board of Ed policy is we teachers have to leave room for them to pass the class. The math generally works like this across most districts that I'm aware of:

WITH THE ACTUAL EARNED ZERO (NOT LIKELY - MY EXPERIENCE IS IT'S USUALLY IN THE '30S OR '40S BECAUSE OF CLASS WORK & ASSESSMENTS) The kid would need to get a MINIMUM 81 EACH quarter AND on the midterm & final just to pass with a 65%.

WITH THE UNEARNED 50%: Each quarter is worth 2/10 of your final grade and the midterm and final is worth 1/10 of your final grade so, if you crunch the numbers, it's 2 * 50 = 100 and then you need 8 * 68 = 552 for a total final grade of 65.2% which is a passing grade.

So here's the question: Do you give them the freebie grade of 50 and only ask them to achieve a 68% average for the rest of the year or so you demand better and measurable improvement and make them work for the MINIMUM 81 for the next 30 weeks?

BEFORE YOU ANSWER KNOW THIS:
1) I have never known a department chair person to say no to a teacher's discretion to change the grade to whatever the most "common good" is; that is to say if the kid doesn't get the minimum 81 to pass but has shown improvement up to say let's say in the low mid-70s or even high 60s, as long as that chairperson gets a heads up on WHAT you're doing it's absolute teacher discretion, the WHY is left to us (correctly I believe) to determine after 40 weeks of being with that student.
2) EVEY ASSIGNMENT IS ONLINE for parents to view 24/7

So what's it going to be? Mediocrity or merit? Freebies or no free lunches? What's the "common good" for the student, the teacher, the school, the parents, the college, future employers and the community and nation at large?