When you have a long list of numbers that are in natural groups, subtotals can be handy. You could have a list of numbers for sales throughout the year and put in subtotals for each month for example. You might have subtotals for each sales person or sub totals for each region or anything like that. All you need is to have the numbers and something to distinguish them into their different groups and have them in the order of their groups. Then you can create subtotals, as Excel will be able to detect the end of one group and the start of the next and then put a subtotal in for the group.

Summary Options

Data menu is that on that we can sort,filter,subtotals,validation,text to columns,pivot tables and pivot chart report

I would call it easy...You can make a graph with a single click of a button and you can do a summary in the form of subtotals with about 3 clicks.

The item list contains the items in the product inventory, sales inventory, services, and special items like subtotals, discounts, and sales tax.

These items appear as line items on purchase and sales forms.