How to calculate a grade in the middle of the term

A question that every professor gets a lot is "What is my current grade in the class?" With the information given in the syllabus, it's really easy to calculate this for yourself. The only hard part for some students is knowing how to deal with the "weighting factor", that is, with the fact that homeworks are weighted at X percent, exams at Y percent, etc. Since we're all engineers, most students can figure out how this works at the end of the term...but how do you take it into account to calculate your current grade halfway through?

To help jog your memory on your applied algebra, this short review of how to do the math should make this a piece of cake for you.

Step 1: Look at the syllabus to see what everything is worth.

As an example to make this discussion concrete, let's assume that you have a syllabus with a weighting schema as follows; just look at the syllabus for your class to see what your exact weighting schema is.

Assignments = 35%
Midterm Exams = 40%
Final Exam = 20%
Participation= 5%

Step 2: Figure out how to calculate your scoring percentage on any given assignment.

You'll need the percentage you scored on each assignment (rather than the raw points you got), but every students knows how to do that: (you score)/(total possible). Ok, so do that for your homeworks, and for your exams so far.

Step 3: Figure out how to calculate your weighted grade...

Ok, so based on the sample syllabus above, this is how your final grade would get computed at the end of the course. Pretty simple weighted sum:

(0.35* <your homework percentage>) + (0.4* <your midterms precentage>) + (0.2* <your final exam percent>) + (0.05* <your participation grade percent>) = your total class percentage

Step 4: Figure out how to compute your grade at any point in the middle of the term

That's pretty easy. But now what about calculating your grade halfway through the term? That's easy too. Let's say that, at some given point, maybe you only have one midterm, some homeworks...and of course no final exam grade and no participation grade. How do we factor that into the weighting formula to arrive at a current percentage partway through the term?

It's pretty simple: you just do the math just like above, except you divide the total by the percentage of (only) the factors you're using up to that point. So let's say that you are partway through the term, and you have some homeworks and a midterm grade. That means you have something in the Assignments (35%) and the Midterms (40%) categories, but nothing in the others. So the total of the ones you have scores in is 35%+40%= 75%

Which means you do this to calculate your current percentage:

( (0.35*<your current homework percentage>) + (0.4*<your precentage on the first midterm>) ) / 0.75 = your current overall weighted percentage in the course.

Piece of cake!