Average homework assignment scores.
Homework assignments are usually out of different totals, so averaging raw marks is wrong — each must be converted to a percentage first. Many courses then drop the lowest one or two scores, which is applied by sorting and discarding from the bottom. Multiplying the resulting average by the homework weight shows the points it actually contributes to the final grade, which is often smaller than students assume.
Normalised average
Each score as a percentage = marks earned / marks available x 100; average = mean of retained percentages
Grade contribution
Contribution = homework average x homework weight / 100
Because an 18 out of 20 and a 9 out of 10 are the same performance, but averaging raw marks treats the first as twice the second. Converting to percentages first is the only correct approach with mixed totals.
Usually yes — many courses require all submissions and only drop the lowest grade, so a missed assignment counts as zero and is not eligible to be dropped.