[Music] welcome to math with mr j [Music] in this video i'm going to cover how to calculate sales tax and then the final price with that tax included let's jump into our examples and see exactly how we do this starting with number one where we have a price of 75 dollars and then a sales tax rate of 8 percent now i do want to mention that sales tax rates vary by country and state and then there can be local taxes that are included as well this video does not cover a specific location sales tax these are general numbers being used to show how to calculate sales tax so the first thing that we want to do is to calculate how much sales tax we will be paying we do this by multiplying the price by the tax rate the tax rate is going to be in the form of a percent we want to get this percent to decimal form percent means per 100 so we divide the percent by 100 to convert it to a decimal we can do this by simply moving the decimal twice to the left so percent to decimal move the decimal twice to the left that gives us a decimal equivalent to the percent so for number one we have eight percent let's move that decimal twice to the left i'm going to rewrite eight percent underneath here so i have enough room now for a whole number the decimal comes after a whole number so it's right here for 8 percent once twice to the left so we have 0.08 for decimal form there so we need to take our original price of 75 75 here and multiply that by 0.08 now if you are using a calculator with a percent button you can also do 75 times 8 percent so you can leave it in percent form just make sure you hit that percent button do not do 75 times eight so either one of those will give us the correct answer as far as how much we are paying in sales tax so 75 times .08 that's going to give us six dollars now 75 times eight percent that gives us the same answer of six dollars so that's how much we are going to pay in tax so once we have that information we take our original price and add that sales tax to give us our final price make sure you add that sales tax so we have i'll write this out by hand we have 75 dollars plus six dollars so that's going to give us a total price with tax included of 81 dollars let's move on to number two where we have 349.99 for our price and then a sales tax rate of 6.75 let's convert that sales tax rate to a decimal move the decimal twice to the left so i'm going to rewrite this underneath here so we have enough room and move it once twice so we have .0675 for our decimal so let's multiply that by our original price of 349. and 99 cents decimal form of .0675 now we can also do this using the percent button on a calculator so i'll write that out just to be clear here so we can do 349.99 times 6.75 percent and these are both going to give us the correct answer of now for this one we get a fairly long decimal so 6 2 4 3 2 5. i'll write that out for both here now we are working with money so money always goes to the hundredths place so if you get a long decimal like this we round to the hundredths place so this two here in the hundredths look next door and we stay the same so this is going to round to let me rewrite it underneath 23. and 62 cents so that's going to be how much we are going to pay in sales tax once we have that information we add it to our original price i'll write this out so we have 304 dollars and 99 cents plus 23 dollars and 62 cents let's add here 9 plus 2 is 11 1 plus 9 is 10 plus 6 is 16 bring our decimal straight down 1 plus 9 is 10 plus 3 is 13 1 plus 4 is 5 plus 2 is 7 and then we have a 3 in the hundreds place so our final price with sales tax included is going to be 373 and 61 cents so there you have it there's how you calculate sales tax take that original price and multiply it by the tax rate either in decimal form or use the percent button on a calculator that's going to give you how much you're going to pay in sales tax once you have that information you take the original price and add that sales tax to get the final price i hope that helped thanks so much for watching until next time peace you