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00:00This video was made in honor of Hattie. I still miss you.
00:06We are learning about double digit subtraction in this video.
00:14You may have watched our basic subtraction video where I gave away my hats, including Hattie.
00:23It got emotional, okay? It just did.
00:26And in that video, we learned that subtraction is when you take numbers away.
00:34Let's say I have six hats, and there's no way that I need six hats that look exactly the same.
00:40Well, good news. Two of my friends need hats, and I decide to give two of my hats away.
00:46When you take numbers away, remember that is subtraction.
00:50If we were to write it out, it would look like this. Six minus two.
00:55So how many hats do I have now if I take two away?
01:04Yes, the answer is four. I have four hats now.
01:12Now this is interesting. The answer to a subtraction problem is called the difference.
01:18Can you say that with us? The difference.
01:21Yeah, the answer to a subtraction problem is called the difference.
01:28That means in our example, the difference is four.
01:36So subtraction is just taking numbers away, and the answer to a subtraction problem is called the difference.
01:46Now that we have that, we want to look at bigger numbers, double digit numbers.
01:54Let's say we have a lot of blueberries. For some reason, they're just hanging out on a wooden table.
02:00We need to wash them and put them in a bowl.
02:05Let's pretend that when we were putting them in the bowl, we counted them and found that we had 66 blueberries.
02:12That's a lot of blueberries. You and your friends are hungry and blueberries are super yummy, right?
02:18So you and your friends eat 54 blueberries. That's right.
02:23These are some big numbers, some double digit numbers.
02:26To find out how many blueberries we have left, we simply subtract 54 from 66.
02:36Let's look at how that's done.
02:41Here is our subtraction problem again. 66 minus 54.
02:46With double digit subtraction, all we do is break this big problem up into two little problems.
02:52First, we will subtract the right column, the ones.
02:56To make it a little easier, we are going to cover the tens column with this blue rectangle.
03:02Suddenly, this big subtraction problem is a really easy one.
03:06What is 6 minus 4? Do you know?
03:14Yes. 6 minus 4 equals 2.
03:17So we put the number 2 under the ones column, the right side.
03:21Great job. We are halfway to our answer.
03:28Next, we will subtract the left column, the tens.
03:32This time, we are going to cover up the ones column to make it a little easier.
03:36What is 6 minus 5?
03:426 minus 5 equals 1.
03:48We will write 1 under the tens, the left column.
03:52Just like that, we have our answer. The difference is 12.
03:56There are now just 12 blueberries.
04:02Alright, let's do another one.
04:07How about 87 minus 53? This should be fun.
04:12First, subtract the right side, the ones.
04:15What is 7 minus 3?
04:21Yes. 4. So we will write 4 under the ones. Simple.
04:28Next, we just subtract the left side, the tens.
04:32What is 8 minus 5?
04:37Yes. 3. So we write 3 under the tens column.
04:46And we have our answer. The difference is 34.
04:53Double digit subtraction is simple.
04:56First, subtract the right, the ones.
04:59Next, subtract the left, the tens.
05:02Then you have your answer, which is also called the difference.
05:08Now, there is something interesting that can happen when you subtract larger numbers.
05:15Here, we will show you.
05:17Say we have this subtraction problem, 22 minus 17.
05:21Let's follow the process.
05:23So first, we subtract the ones.
05:26What is 2 minus 7?
05:28Well, here is that interesting thing we mentioned to you.
05:31Say I have 2 carrots, and I need to give 7 carrots away.
05:35That's a problem. It's hard to give away more than you have.
05:39So what do we do? Well, we do a special trick.
05:45No, not this kind of trick. Wow, he is really high up there.
05:50No, not this kind of trick either, alright?
05:53It's a math trick, okay? It's a math trick.
05:55This is a subtraction video after all.
06:01The trick is called regrouping. Can you say that? Regrouping.
06:06Yeah, regrouping.
06:10When you are subtracting a column, and the bottom number is bigger than the top number,
06:16that means you need to regroup.
06:18Just like in this example, because it is hard to take away more than you have,
06:24and 7 is bigger than 2, so we need to regroup.
06:32So how does this regrouping trick work?
06:35It's really easy. All you do is borrow 1 from the tens column.
06:41What is 2 minus 1?
06:45Yeah, 1. So this number in the tens column becomes a 1.
06:50And that 1 that we borrowed from the tens, it goes to the ones.
06:54It gets placed on this 2 in the ones column.
06:57And now the ones column is 12 minus 7.
07:03Now we just have to follow our subtraction game plan.
07:07We subtract the right column, the ones first.
07:11What is 12 minus 7?
07:15Hmm.
07:17Yes, 12 minus 7 equals 5. So we write the number 5 under the ones column.
07:23Then of course we have to subtract the tens.
07:26But regrouping made this super easy.
07:29What is 1 minus 1?
07:32Yes, 1 minus 1 equals 0. So our answer is simply 5.
07:385 is our difference.
07:42Remember, when you are subtracting a column and the bottom number is bigger than the top number,
07:48that means you need to regroup.
07:50And with subtraction, regrouping means borrowing.
07:58In double digit subtraction, regrouping is when you borrow 1 from the tens column.
08:06Let's try one more double digit subtraction problem and see if we need to use the special regrouping trick.
08:1443 minus 25. This is going to be awesome.
08:18Remember, the first thing we do is subtract the right column, the ones.
08:22But uh oh, 5, the bottom digit, is bigger than 3, the top digit.
08:29Time to regroup.
08:32So we borrow 1 from the tens column. What is 4 minus 1?
08:38Yes, 3.
08:40Then we put that 1 in front of the 3 in the ones column, making it the number 13.
08:49Then we just follow the process, subtracting the ones column first.
08:55What is 13 minus 5?
08:58What is 13 minus 5?
09:01What is 13 minus 5? Yep, it is 8.
09:06So we will write 8 under the ones column.
09:13Now it's time to subtract the tens. What is 3 minus 2?
09:19What is 3 minus 2? You got it.
09:223 minus 2 equals 1.
09:25So we put the number 1 under the tens column and we have our answer.
09:3043 minus 25 equals 18.
09:3518 is the difference.
09:38We've learned a lot, but we need to make sure we are able to remember everything.
09:44Here's an idea.
09:47There's this guy, Mummy, who doesn't know how to do double digit subtraction.
09:54So we are going to do a double digit subtraction review by teaching Mummy.
10:01It's simple and it's fun, Mummy. You'll love it.
10:06So Mummy, subtraction is when you take numbers away.
10:10Sometimes subtraction problems can have little numbers.
10:13Other times, subtraction problems can have bigger numbers, double digit numbers.
10:18Here's how it works, Mummy.
10:20First, subtract the right column, the ones.
10:23Next, you subtract the left column, the tens.
10:26Then you have your answer, which is called the difference.
10:34Sometimes the bottom digit is bigger than the top digit in the ones column.
10:38This is something to get excited about, Mummy.
10:41It means you can use a special trick called regrouping.
10:45You just borrow one from the tens column and move it to the ones column.
10:51Then just follow the plan.
10:59Thanks for helping us teach Mummy. He looks happy.