Weighted average grades are a way for a teacher to place more importance on one assignment than another. For example, if a student scores 100 on a test worth 30 percent of his grade and 50 on a test worth 70 percent of his grade, then the 50 score will have a bigger impact than the 100 score on the final grade. You can use Microsoft Excel to quickly make these calculations.

Type "Grade" in cell A1, "Weight" in B1 and "Total Worth" in C1.

Type your grades in column A. For example, if you received a 95 and an 80, then type "95" in A2 and "80" in A3.

Type the weight each grade has in column B, next to its corresponding grade. In the example, if the first grade is worth 60% and the second grade is worth 40%, then type 60% in B2 and 40% in B3.

Type "=A2*B2" in cell C2. This weights the grades. Copy and paste this formula next to each grade.

Type "=sum(" in column C after your last grade, then highlight all the cells that have a number in coumn C and hit the "Enter" key. The result that appears is your weighted average.