If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:2:49
CCSS.Math: ,

Video transcript

let's divide 7180 two by forty two and what's different here is we're now dividing by a two-digit number not a one digit number but the same idea holds so we say hey how many times does 42 go into seven well it doesn't really go into seven at all so let's add one more place value how many times does 42 go into seventy-one well it goes into 71 one time and we're really just two reminder we're just doing the process we say hey 42 goes into 71 one time but we're really saying 42 goes into 70 100 100 times because we're putting this one in the hundreds place but let's put that on the side for a little bit and focus on the process so 1 times 42 is 42 and now we subtract now you might be able to do 71 minus 42 in your head knowing hey 72-42 would be 30 so 71 minus 42 would be 29 but we could also do it by regrouping to regroup you want to subtract a 2 from a 1 well that's not so you can't really do that in any traditional way so let's take a 10 from the 70 so that becomes a 60 and give that 10 to the ones place and then that becomes an 11 and so 11 minus 2 is 9 and 6 minus 4 is 2 so you get 29 and we can bring down the next place value bring down an 8 and now this is where the art happens when we're dividing by a multi digit number right over here we have to estimate how many times does 42 go into 298 and sometimes it might involve a little bit of trial and error so you really just kind of have to eyeball it if you make a mistake try again the way you know you make a mistake is if you say it goes into a nine times and you do nine times 42 and you get a number of larger than 298 then you overestimate it if you say it goes into it three times you do three times 42 you get some number here when you subtract you get something larger than 42 then you also made a mistake and you have to adjust upwards well let's see if we can eyeball it so this is roughly 40 this is roughly 340 goes into 300 the same times as 4 goes into 30 so it's going to be roughly 7 roughly 7 let's see if that's right 7 times 2 is 14 7 times 1 is 28 plus 1 is 29 so it got pretty pretty close my remainder here notice 94 is less than 200 my remainder is less than 42 so I'm cool as well so now let's add another place value let's bring let's bring this two down and here we're just asking ourselves how many times does 42 go into 42 well 42 goes into 42 exactly one time one times 42 is 42 and we have no remainder so this one luckily divided exactly 42 goes into 7180 - exactly 171 times