in this video we're going to talk about how to use absolute cell references when performing calculations in excel so let's say we have these two columns of data and we want to multiply the information in column 1 by column 2. so we can start by selecting cell b5 let's multiply by cell c5 so 15 times 18 that's 270 and if we click this button on the right on the bottom right and if we extend it we can multiply the entire column data 1 by the data 2 column now let's say if we have some number in a cell e2 let's say it's 30. and we want to multiply theta 1 by 30. so we can type in equal b5 times e2 and so that's 15 times 30 that's 450 but notice what happens if we try to extend it for the entire column notice cell d6 doesn't show the value for 28 times 30. so what happened here what's going on well to see what's happening let's look at the formulas you could probably see it here but if you go to formulas and then go to show formulas notice that it's not always multiplying by e2 here we have b5 being multiplied by e2 and here b6 is multiplied by e3 and cell e3 doesn't have anything and so what we can see is that all the numbers are changing e2 e3 e4 e5 e6 so we need to change it from a relative reference to an absolute cell reference so how can we do that now we could change everything to e2 but is there a way that it will always be e2 once we use this button and fill it down to the rest let's go back to formulas let's click show formula and let's delete this what we need to do is create an absolute cell reference and if you put a dollar sign in front of the letter e and in front of the two it's going to lock that cell once we extend it so now let's click the button on the bottom right and then extend it so notice that we're multiplying data one by thirty so if we go back to show formulas so this time notice that we always see e2 it doesn't go to e3 e4 e5 it's locked in cell e2 and so that's one way you could use the absolute cell reference feature in excel so if you want to multiply by a certain cell and if you want to extend it without changing that particular cell you could use the absolute cell reference by putting a dollar sign in front of the e and in front of the two if you put it in front of the e it's going to be locked across columns when you copy it and if you put it across the two it's locked across rows to illustrate this let's go ahead and remove the dollar sign in front of the e and let's extend it so notice that it remains e2 as we copy it across rows so it's still work it didn't change now let's see what's going to happen if we put the dollar sign in front of the e and now let's extend it notice that it didn't work it wasn't copied across rows six seven eight and nine so if you want to copy across rows you need to put the dollar sign in front of the two if you want to copy it across columns like this you need to put the dollar sign in front of the e and that's if you want to do one but not the other but if you want to do both just put the dollar symbol and cross i mean in front of the e and a two and so that's how you could use absolute cell references when extending a formula across a bunch of rows or columns so that's it for this video thanks for watching you