You can total things in many ways. Put the cursor at the cell below a list of cells with values and click the Autosum. You can also select the block of cells you want to get totals for and click the Autosum. If you have a number of columns selected, totals will be put in for all of them. You can also select a blank row under a table of values and click Autosum and it will put a total for each column. The same things can be done to total rows.
auto sum
By using addition.
The sum is where two or more numbers are added together to give a total.
In order to know which operation, you have to find the keywords. EX: how many more, difference, sum, total, etc.
Since you put this question in the Excel category, I will answer relative to what you can do with Excel. The quick way is to highlight the column of numbers and click on the Auto-Sum button.
If you are using Microsoft Word Excel then you could just use the Auto Sum.
Assuming you're using Microsoft Excel, select the entire column by clicking and dragging with the mouse, then press the AutoSum button (looks like Σ).
why is necessary to auto-save
Yes, you can do that. If you have a series of columns, you can highlight all of the column to select the range. When you click on the auto-sum button, Excel will insert =SUM(XX:XX) at the bottom of each column in the range.
Using the formula: (number of sides -2)*180 = sum of interior angles
(number of sides - 2)*180 = total sum of interior angles
You square each number and multiply that by the frequency with which that number appears. You then sum together these results.