Double-check your work the smart way

When double-checking your work, use a different method than the one you used to calculate the figures in the first place.

For example, back in the day before advanced computing, you might have added up figures from a bank statement to prepare a GST return. To check it, you’d work backward – compare the totals on your adding machine tape back to the bank statements.

Use common sense, too. Does the number look reasonable? Is it close to what you’d expect?

Sometimes, you just need a rough idea to know your total is likely to be accurate. For instance, if you have a column of numbers ranging from $1 to $5000, you can estimate like this:

• if it’s $500 or less, count it as $0
• between $500 and $1499, count it as $1000
• from $1500 to $2499, count it as $2000, and so on.

With this method, you can quickly get a rough total in your head without needing an adding machine.