If you have an 87% what will a 0% do to it?

If you only have that 1 87 and a 0 just average them, if not we need to know your other scores or what % of your grade the 0 is

Depends on the grading system of the school or instuctor, and how much the grade you got today counts towards the total of the grade.

You should look into making that grade up if you can. A 0 can take your grade down pretty quick.

Nothing good.

Assuming equal weights, your average now is 43.5%.

You said the 87% is an average. So, it does not matter whether we got that via let’s say, 5 scores of 87 each, or 85–86-87–88-89. Either way you have an 87 average.

Now, I assume that each assignment is equally weighted. So, take 87 and multiply it by the number of assignments (I’ll call this variable “n”) to get your total number of points (or just use your total if you know). Again, since 87 is an average, your actual scores do not matter.

Now just take however many total points you got and divide that by the number of assignments plus 1. This is your new score.

An e.g. with 5 assignments
Total score=5*87=435
Number of assignments=5

So, your new grade is 435 / (5+1) = 72.5

No offense, but you should really start paying more attention in math class to learn how to calculate averages yourself.

@Mamradpivo , Weighted averages are not taught in schools.

I was taught weighted averages in my school. Probably in algebra 1