Grading Formula

Hello

I'm building a spreadsheet that will allow my classmates to enter the mark they get on a test/quiz/assignment and have it automatically tell them the weight of the toal course mark they've earned.

I have a formula in place to SUMIF the active weights (assignment/tests/quizzes we have marks for), a formula to sum the total weight they've earned, and a formula to show them what they're currently getting in the class (simple divide weight earned by current active weight)

Right now, if someone enters their mark, they have to manually determine what amount of the weight for that task they've earned. I want to fix the sheet so that when they enter their mark it automatically tells them what weight they've earned for that assignment.

Right now, I can get it to automatically show the weight earned if a mark is entered as a whole fraction (29/30), decimal (5.67, 0.71) or whole number (6). What I can't do is get it to automatically calculate the weight if the mark is entered as a decimal fraction (3.5/5). It's fine if I put an = in front of the 3.5/5, but I don't want my users to have to enter an =. If I leave an = in the cell for them, it will be removed when they select the cell and enter information, because they won't go to the function bar.

What can I do? Is there a way to lock an = into the cells of the "Marks" column so when they select the cell and enter their mark it doesn't remove it? Or is there a way to have it automatically convert a decimal fraction to a decimal number the same way it does for a whole fraction? What can I do?

Unfortunately this will not work for me. I have all the assignment/tests/quizzes that we have done and will be doing in the class listed. If I apply the formula for the DECIMAL column to all the cells in the range, I get a #div/0! error for tasks we don't have a mark for yet, and the OUT OFis unknown until we actually get the mark for the task.

With a #div/0! error in the DECIMAL cell, I get a #div/0! error in the Weight Earned cell, and that carries to the Total Weight Earned cell, and the Current Grade cell, which defeats the purpose of the spreadsheet itself.

I can't not apply the formula, because I just want the user to enter their mark, not have to do calculation and apply formulas, again defeats the purpose of the sheet.