Percentage Known
Use this method on your calculator if you need to work out a certain percentage of an amount.
E.g. What is 40% of 200? (80)
To solve this, you multiply the percentage by the amount (40 x 200), and then divide this by 100 (/ 100). Watch this animation for the buttons to hit:
There is an even faster way that we prefer. Simply, before you even touch the calculator, you convert 40% into a decimal value by dividing it by 100. 40/100=.4 in this case. (Remember maths class, you’re just moving the decimal point two places to the left).
Here’s the pattern for doing these conversions: 5% = .05, 10% = .1, 20% = .2, 25% = .25, 80% = .8, etc.
Now, multiply the percentage-as-decimal value by the amount (.4 x 200), and then hit the equals button. Easy! You don’t have to divide by 100 at the end because you have already taken care of this when you turned 40% into .4
