Customize reports and doctypes
**Note: Refer for qty, rate column change: erpnext/erpnext/public/js/controllers/taxes_and_totals.js
calculate_item_values
Also edit taxes_and_totals.py
if ((!item.qty) && me.frm.doc.is_return) {
item.amount = flt(item.rate * -1, precision("amount", item));
} else {
if(item.sqft){
item.amount = flt(item.rate * item.qty * item.sqft, precision("amount", item));
}
else{
item.amount = flt(item.rate * item.qty, precision("amount", item));
}