welcome to adding and subtracting decimals with mr. J in this video we're going to be discussing how to add and subtract decimals and the steps we need to take in order to successfully do so on your screen you see four problems two addition and two subtraction we're going to work through these four together and if at any point you want to try a couple on your own feel free to press pause solve the remaining problems or whichever problems you want to solve press play when you're ready and check your work with mine at the top of your screen in blue you see the steps to adding and subtracting decimals so keep those in mind as we work through so let's jump right in to number one so for number one we have forty five and six tenths plus three and eighty nine hundredths so our first step we need to set the problem up rewrite it vertically or up and down and we need to line up the decimals so we'll write out 45 and six tenths plus three and 89 hundredths the decimals are lined up there for all the places are lined up now we can insert placeholder zeros if need be so take a look at the nine it's kind of hanging off to the right the three and 89 hundredths goes to the hundredths place so we want the 45 and 6/10 to go to the hundredths place too that way we have something above the 9 there and it lines up a little better you can add zeros to the right of a decimal and it does not change the value of that number so again you can use placeholder zeros to the right of a decimal and it doesn't change the value this only works for decimals though you can't add zeros to the right of whole numbers or else it does change the value so use placeholder zeros and then we can add or subtract so 0 plus 9 is 9 6 plus 8 is 14 carry the 1 bring your decimals straight down it should be lined up throughout the whole problem 1 plus 5 is 6 plus 3 is 9 and then 4 so 49 and 49 hundredths number 2 we have 15 plus 4 + 88 hundredths so for a whole number we put the decimal right after it now we can line up four and 88 hundredths and this is addition so here the problems offset like number one we had to use placeholder zeros so for the 15 we could put a zero in the tenths and a zero in the hundredths now we're all lined up and ready to add 0 plus eight is eight zero plus eight is eight bring the decimal straight down 5 plus 4 is 9 1 plus 0 there is 19 or I'm sorry you have the 1 there which gives us 19 so 19 and eighty-eight hundredths so number three we have subtraction which it's the exact same rules except when you get to this third step over here you subtract so let's write out our problem lining up the decimals and it's subtraction so let's put the placeholder 0 there and now it's time to subtract so we cannot do 0 minus 7 so we need to borrow so now we have 10 minus 7 which is 3 cannot do 5 minus 6 so we need to borrow so we get to 15 minus 6 which is 9 bring the decimal straight down so we need to borrow again we can't do 4 minus 9 so we need to borrow from the 3 or the tens place here and we get 14 minus 9 which is 5 and then we have the 2 so 25 and 93 hundredths line up the decimals use placeholder zeros add or subtract so just like number 2 here we have a whole number in number 4 so the 23 and we put the decimal right after then we have 8 and 8/10 and subtract so let's put the placeholder 0 and we are ready to solve so we can't do 0 minus 8 don't just drop the 8 there we need to borrow 10 minus 8 is 2 decimal straight down and we need to borrow again so 12 minus 8 is 4 and then we have the 1 so 14 and 2 tenths so that's adding and subtracting decimals for you and the rules or steps we need to take in order to get to the correct answer so make sure you line up your decimals use placeholder zeros and then add or subtract thanks so much for watching until next time peace