How do i do percentage stuff in my head ex. something that is on sale?

Question

like when i go to the store and i want to buy something and it says something % off how would i do that in my head?

Answer 1

Calculate by 10 percent at a time. For example: something that cost $48.00 and is marked 30 percent off - 10 percent of $48.00 would be $4.80. So $4.80 multiplied by 3 would equal approximately $15.00 (then you can deduct the .60 cents off of that) = $14.40 (30%). If it is 25 percent off just do the 10 percent thing twice and then half of the 10 percent to get the 5 percent.

I hope this made sense to you! I find this a very easy way to calculate percentages.

Answer 2

There's no super-easy method to handle ALL percentage discounts ... unless you have a calculator.

BUT, here are some suggestions:

Start by rounding the price to make it easier to work with. If it's $15.95, use $16. If it's $98, call it $100.

Usually the discount is a percentage that ends in 0 or 5 (e.g., 20%, 15%, 40%, etc.).

If the discount percent ends in 0:
Start by figuring out what a 10% discount would be. (For example, if the regular price is $60, 10% is $6. You just move the decimal point one place to the left. (Or drop the ending 0.))

Once you've figure out what 10% would be, increase that amount to reflect the actual discount percentage is. If the discount is 20%, double the 10% amount. If it's 40%, multiply it by 4 (or double it twice).

Now that you know the dollar amount of the discount, you need to subtract it from the original price.

If the discount is more than half (60%, say), instead of calculating the discount amount and subtracting, just calculate the NET price directly (40%, in the case of a 60% discount).

If the discount percent ends in 5, you have to consider an amount equal to HALF of 10 percent. For example, if it's a 15 percent discount, it's equal to 10 percent plus half of 10 percent. If the original price rounds to $80, 10 percent is $8 and half of that is $4. So the total discount is $12. The net price is $80 less $12, which is $68.

Also, you often see 50% or 25% discounts. These are just a half or a quarter of the original price. You can divide the price by 2 for 50%. For 25%, divide it by 4 (or divide by 2 twice).

Hope this gives you enough ideas to handle most situations.
Good luck.

Answer 3

http://www.staff.vu.edu.au/mcaonline/units/percent/pereve.html

on the bottom of this page show examples of how you use them in sales or tax. hope this helps