To calculate percent of a total ie. If you are using Excel for the web click Home Number Format Percentage. To calculate the difference as a percentage we subtract this months value from last months and then divide the result by last months value.
Hit Enter to get the students score as a percentage of the total possible points.
For example if you want to calculate 20 of 500 multiply 20 by 500. Number percent 100. We want to show the total estimated amount not just the increase. The answer 67 should appear in cell E6.