An example of my skill in Microsoft Excel:
I constructed a spreadsheet of my gasoline use over time.
I entered only
[1] Date
[2] City
[3] Millage
[4] Gallons
[5] dollars
and Excel formula automatically calculated
[1] Miles traveled since start
[2] Miles between gas purchases
[3] Miles per gallon since last gas purchase
[4] Accumulated Gallons since start
[5] Accumulated Dollars since start
[6] Accumulated Dollars per month
[7] Average miles per gallon since start
[8] Average dollars per gallon since start
[9] Average Miles per dollar since start
[10] Average Miles per Day since start
[11] Average dollars per Day since start
[12 Average gallons per Day since start
[13] Is this last time bought gas this month?
[14] Days since started recording
[15] Days since last gas refill
[16] Average number of days use for each refill of tank