What's my grade right now?

Here's a discussion about how the grade for this course is calculated. You can calculate your current grade if you like. This is an ideal problem for a spreadsheet, or you could write a java program to do it. Or, do it the old-fashioned way - with a pencil and paper.

 

Weighted averages

Many of your courses use a weighted average, so once you understand how they work, you can calculate midterm grades for any course. A weighted average is a way of giving more importance, or weight, to some coursework. For example, the final exam is often worth more than labwork. The final exam has a higher weight.

Here are the weights for the grade in this course:

  Labs, Reading, and participation 10%
  Quizzes 10%
  Lab Quizzes 15%
  Homework 20%
  Exams (10% each) 20%
  Final Exam 25%

 

Partial weighted average

If you're interested in calculating your grade so far in a course, you don't yet have all the grades in, and thus, your weights don't add up to 100% (as they will at the end of the semester). But to calculate an accurate partial score, you'll need to take the weight into consideration. To do this, add up the weights of the grades that you have completed. You'll divide your calculated grade by that number once you calculate your weighted average of the grades you are using to compute your partial grade.

 

An Example

First you will need to calculate a straight average for each portion of the course: Labs, quizzes, lab quizzes, and homework.

Labs

Add your lab scores together and divide by the number of points possible for those labs, and multiply times 100. Example:

L01a L01b L01c L02a L02b .... L10b L11a L11b L12a
10 9 10 10 0   9 8 10  

Don't add in labs that have not yet been graded. Suppose 20 labs have been graded so far. 200 points are possible for those labs. Suppose your scores, added up, for those labs is 183 (missed labs are zeroes). Then your lab average would be 183/200 * 100, which is 91.5.

Reading and participation

Reading consists of the reading quizzes. If you completed a reading quiz, you get 100% credit for that quiz regardless of whether or not your answers were correct. Figure out the average of the reading quizzes you completed. (9/10 reading quizzes would be 90%).

Participation consists of your attendance grade, as recorded on your attendance card. Estimate the percentage of classes and labs you attended. Let's assume 80% attendance for our example.

Average your reading and attendance percentages together. (90 and 80 would be 85%.)

Quizzes

This refers to the weekly quizzes on D2L. Add your quiz scores together and divide by the number of points possible for those quizzes, and multiply times 100. Example:

Quiz1 Quiz2 Quiz3 Quiz5 ... Quiz10
100 92 94 88   80

Of course you are only adding up the scores of the quizzes you have taken so far, and dividing by the total possible of the quizzes taken so far. Each quiz is worth 100 points. Suppose 10 quizzes have been taken so far, and suppose this person's total is 940. This quiz average is 940/1000 * 100, which is 94.

Lab Quizzes

Add your lab quiz scores together and divide by the number of points possible for those lab quizzes, and multiply times 100. Example:

LQ1 LQ2 LQ3 LQ4 LQ5 LQ6
10 9 0 10 7  

In this example, there are 50 points possible on the 5 lab quizzes that have been taken and graded so far (missed lab quizzes are zeroes). This lab quiz average is 36/50 * 100, which is 72.

Homework

Add your homework scores together and divide by the number of points possible for those homeworks, and multiply times 100. Example:

HW1 HW2 HW3 HW4 HW5 HW6 HW7 HW8
25 75 100 90 94 92    

HW1 was worth 25 points, and HW2 was worth 75 points. In this example, there are 500 points possible on the 6 homework asisgnments that have been taken and graded so far. This homework average is 476/500 * 100, which is 95.2.

 

Calculate your semester average so far

Take your lab average and reading and attendance average and average them together. in this example, 91.5 and 85 is 176.5. 176.5/200 * 100 is 88.25. This number is worth 10% of your grade.

Add all your averages, multiplied by their weights:

(Lab/Reading x .10) + (WeeklyQuiz x .10) + (LabQuiz x .15) + (HW * .20) + (Exam1 x .10) + (Exam2 x .10)

Suppose this person got 102 on Exam 1 and 64 on Exam 2. In this example:

(88.25 x .10) + (94 x .10) + (72 x .15) + (95.2 x .20) + (102 x .10) + (64 x .10)

8.825 + 9.4 + 10.8 + 19.04 + 10.2 + 6.4

64.665 is the total

But, this number only acounts for 75% of the grade, because the final exam has not been taken. If you add the weights, you get 0.75. So now you need to divide by that number.

64.665/0.75 is 86.22, which is a good indication of this person's current grade.

 

What do I need to get on the final exam?

Most students want to have an idea what they need to get on the final exam in order attain a particular percentage in the course. Here's an easy way to think about this: Because the final exam is worth 25% of the grade, or, one fourth, it takes 4 points on the final exam to move this final semester average up one point.

So in this example, we have an 86.22 average so far in the class. Let's call that 86. If this person scores an 86% on the final exam, they still have an 86. If they score a 90% on the final exam, they will be able to pull their average up 1%, to an 87. A 94% would earn them an 88. A 98% would pull their grade up to an 89. Probably, this person is looking at a B for the course, but it is mathematically possible to pull their grade up to an A (because it is possible to score more than 100 on the final exam).

Maybe you'd like to think about how low of a score you can earn on the final exam before you drop a letter grade for the course. It takes 4 points on the final exam to budge the semester average one point. So, an

So, this student could score as low as 62 on the final exam and still be assured of maintaining a B in the course.

86.22 x .75 + 62 x .25

64.665 + 15.5

80.165

 

How do I calculate this number?

Of course you can calculate this if you like, instead of estimating grades. The formula is:

Average_so_far_this_semester x .75 + Final_exam_score x .25 = Semester_average

If you want to see what you need to make on the final exam to make particular average in the class, simply plug in the Semester average you want to get, and solve the equation for Final_exam_score.

Average_so_far_this_semester x .75 + Final_exam_score x .25 = Semester_ave

(Average_so_far_this_semester x .75) / .25 + (Final_exam_score x .25) / .25 = Semester_ave /.25

Average_so_far_this_semester x 3 + Final_exam_score = Semester_ave /.25

Final_exam_score = Semester_ave /.25 - Average_so_far_this_semester x 3

 

Using our example, let's say we want to see what we need on the final exam to make an 80 in the class:

Final_exam_score = 80 / .25 - 86.22 x 3

Final_exam_score = 80 / .25 - 86.22 x 3

Final_exam_score = 320 - 258.66

Final_exam_score = 61.34

Using our example, let's see what this student would need to make a 70 in the class:

Final_exam_score = 70 / .25 - 258.66

Final_exam_score = 280 - 258.66

Final_exam_score = 21.34

Using our example, let's see what this student would need to make a 90 in the class:

Final_exam_score = 90 / .25 - 258.66

Final_exam_score = 360 - 258.66

Final_exam_score = 101.34