How to take 20% off a number on a calculator?

Slashing Prices: The Easiest Way to Calculate a 20% Discount

Need to quickly calculate a 20% discount on a price? Forget complicated mental gymnastics or hunting for a sale calculator app. This simple method uses only your standard calculator and a touch of mathematical savvy. No more fumbling with percentages – let’s get to those savings!

The key lies in understanding that percentages are simply fractions expressed as a part of 100. 20% means 20 out of 100, or 20/100. This fraction simplifies to 1/5, but we’ll use the decimal equivalent for ease of calculation on a calculator.

Here’s the step-by-step process:

1. Convert the percentage to a decimal: To convert a percentage to a decimal, simply move the decimal point two places to the left. So, 20% becomes 0.20 (or just 0.2). This represents the fractional part of the original price you’ll be subtracting.

2. Multiply the original price by the decimal: Take the original price of the item and multiply it by the decimal you just calculated (0.2). This calculation gives you the amount of the discount itself.

3. Subtract the discount from the original price: Finally, take the result from step 2 (the discount amount) and subtract it from the original price. This will give you the final price after the 20% discount has been applied.

Let’s illustrate with an example:

Imagine a shirt costs $50. To calculate the price after a 20% discount:

1. 20% as a decimal: 20% = 0.20

2. Multiply by the original price: $50 x 0.20 = $10 (This is the discount amount)

3. Subtract the discount: $50 – $10 = $40 (This is the final discounted price)

Therefore, the shirt will cost you $40 after the 20% discount.

A quicker method (for those comfortable with mental math):

Since subtracting 20% is the same as calculating 80% of the original price (100% – 20% = 80%), you can directly multiply the original price by 0.80 to arrive at the final discounted price. Using our example: $50 x 0.80 = $40.

This method is faster but requires a slightly better grasp of percentage concepts. Choose whichever method feels more comfortable and efficient for you. The important thing is to get that discount!