Lessons · Teaching · a weighted grade
A weighted grade
A weighted grade multiplies each category's score by that category's weight and adds the results; the weights add to one, and if they do not, the grade is wrong before you start.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
What it is for
A parent email at nine at night: how is she on 78 when every test was in the eighties? You need to answer that in four lines, tonight, with the arithmetic visible. A grade you cannot explain is a grade you cannot defend.
How to think about it
Three columns: category, weight, score. Check the weights add to 1.00 before anything else. Then multiply across each row and add the column down.
Worked example
Tests 0.40 × 86 = 34.4Weight times score, one row at a time.
Quizzes 0.25 × 92 = 23.0The same move again.
Homework 0.20 × 70 = 14.0The row that usually surprises the reader of the email.
Projects 0.15 × 80 = 12.0, and the four rows total 83.4%The weights 0.40, 0.25, 0.20 and 0.15 add to 1.00, which is the first thing to check.
Your turn
One category carries a weight of 0.30 and the score in it is 60. Write the line that gives that row's contribution.
0.30 × 60 =
Solve one, graded on the server
The trap
Averaging the category averages. Four categories of 86, 92, 70 and 80 give 82 straight and 83.4 weighted, and that gap is somebody's grade boundary.