The Joy of Spreadsheets

Some very obvious things are learnt late in life. Today's addition to the list of Things I Should Have Figured Out A Long Time Ago is that if you are adding up long columns of figures on a computer, the best way to do it is to open a spreadsheet, type them all in, then put a nice little sum formula at the bottom of the column. This means that if you make a mistake, you can just rewrite the previous cell, rather than swear profusely and bang your head against the wall.