Brief Summary
This video provides a step-by-step guide on how to calculate a discount by hand and determine the final sale price without using a calculator. It covers converting the discount percentage to decimal form, calculating the discount amount, and subtracting the discount from the original price to find the sale price.
- Convert discount percentage to decimal form by dividing by 100 (moving the decimal point two places to the left).
- Multiply the original price by the decimal form of the discount to find the discount amount.
- Subtract the discount amount from the original price to calculate the final sale price.
Calculating the Discount
To calculate the discount amount, multiply the original price by the rate of discount. The rate of discount is given as a percentage, which needs to be converted to decimal form by dividing the percent by 100. This conversion can be done by moving the decimal point two places to the left. For example, 35% becomes 0.35 in decimal form.
Multiplying to Find the Discount Amount
To find the discount amount, multiply the original price ($78.95) by the decimal form of the discount (0.35). When multiplying decimals, the decimals can be taken out temporarily and then placed in the answer once the multiplication is complete. After multiplying 7895 by 35, the result is 276325. Since there are four digits to the right of the decimals in the original problem (two in each number), place the decimal four digits from the right in the result, yielding 27.6325.
Rounding the Discount Amount
Since we're working with money, the discount amount needs to be rounded to the hundredths place. In the number 27.6325, the digit in the hundredths place is 3. Looking at the digit to the right (2), it indicates that the 3 should stay the same because it is less than 5. Therefore, the discount amount is $27.63.
Calculating the Sale Price
To find the final sale price, subtract the discount amount from the original price. The original price ($78.95) minus the discount ($27.63) is calculated by lining up the decimals and subtracting each place value. This gives a sale price of $51.32.
