One way to find a percentage of an amount is to remember that 1 per cent of an amount is one hundredth of it. So to find 1 per cent of an amount, you can divide it by 100. Once you know \(1\%\) of ...

We want to calculate the percentage of annual decline ... We use half because the formula tells us to divide one by the number of years difference between the two numbers; in this case, that's ...