Video instructions and help with filling out and completing Form 2220 Subtracting

Instructions and Help about Form 2220 Subtracting

Hi and welcome to math antics in this video we're gonna learn how to do multi digit subtraction it's similar to doing multi digit addition like we learned in our last video but there's a few important differences the main difference is with subtraction the order of the problem matters with addition you can switch the order of the numbers you're adding and you'll still get the same answer five plus two equals seven and two plus five equals seven but with subtraction if you have the problem five minus two you'll get three but you can't switch the problem around you won't get the same answer if you try to do two minus five instead in fact you'll probably get confused because you'll be trying to subtract a bigger number from a smaller one with multi digit subtraction it's important to remember that order matters especially when you're rewriting your problem often you'll be given a problem like this 38 minus 25 and you'll have to rewrite it with the numbers stacked up like we did with addition but you have to make sure that the first number the one you're taking from goes on top and the number you're taking away is on the bottom another hint is that the bigger number should always be on top okay let's go ahead and try this card we've got 38 on top and 25 below it and the ones places are lined up just like they should be now we draw our line so our answer can go below it and we write a minus sign over here on the left to show that we're subtracting now we can start getting our answer and just like with addition we always start with the ones place column here we subtract the bottom number from the top eight minus five equals three so the three goes in the ones place of our answer now we move to the next place column to the left the tens place there we have three minus two which is one there we just subtracted 25 from 38 and found out that the difference is 13 all right let's see another example 135 minus 27 aha this is where multi digit subtraction can get a little tricky let's rewrite our problem 135 on top 27 below it with the ones places lined up neatly and our answer line and subtraction symbol in place there now we can start subtracting oh look at this in our ones place column the digit on top is smaller than the digit on the bottom how can we subtract a bear digit from a smaller one did we make some kind of mistake no we wrote our problem correctly the bigger number is on top sometimes this just happens the top digit might be smaller than the bottom digit so you can't subtract it unless you borrow here's how borrowing works the top digit is five but the digit below it wants to take seven away sorry I don't have seven I um have five well what about your neighbor he's in a bigger number place he's loaded so you can just borrow from him excuse me I've got a little problem do you happen to have something I could borrow why of course here you go great that one will help but if you just add one to five you'd get six but fortunately this one came from the next number place and it really represents a ten and when we add ten to five we get 15 which is big enough now instead of this column being five minus seven it's 15 minus seven and fifteen minus seven equals eight okay we've got the first digit of our answer now we could move on to the next column but remember we borrow from that number place it used to be a three but now it's a two it went down by one because we borrowed from it well remember we really borrow ten because it was in the next number place but it's sometimes easier to just think of it as borrowing a one and getting to stick that one and threaten the digit that needed to borrow so in the tens place we have 2 minus 2 which gives us zero in our answer and then our last column just has one minus nothing or one minus zero so that's still just one there we've calculated that the difference between 135 and 27 is 108 all right let's try another example with borrowing or regrouping as some teachers call it let's subtract 58 from 426 again we start by subtracting the digits in the ones place column here we have 6 minus 8 and since 6 is too small to subtract 8 from we'll need to borrow we always borrow from the number place on the Left we'll borrow a 1 which is really a 10 and will write it in front of our borrowing digit in this case 6 which gives us 16 and don't forget to make the digit we borrowed from smaller by one you can just cross it out and write the new smaller number above it like this okay now we can subtract from the first column 16 minus 8 equals 8 now for the tens place since we borrow from this column it's become 1 minus 5 but again the top numbers too small so we'll have to borrow again we borrow a 1 from the next number place over which means that digit will change from 4 to a 3 then we put the 1 in front of the borrowing digit which will make it 11 now we can do the subtraction for that column 11 minus 5 equals 6 and the last column is easy we bring that left over 3 down to the answer line because there's nothing there to subtract from it and that means 368 is our