Skip to playerSkip to main contentSkip to footer
Edu-Primes
  • 9/18/2024
Transcript
00:00Hi kids, today we are going to learn about regrouping with subtraction. Let's jump right
00:10in and get to learning. We are going to use place value to help us
00:18solve these problems today. In this problem, there are 45 students on the school bus. 17
00:25students got off the first bus stop. How many students are left on the bus?
00:30To get started on this problem, let's first line the numbers up correctly.
00:36If we look at the 4 in the 10s place, we need to remember that this represents 40 since
00:40it is in the 10s place. The same goes for the 1 in 17. This 1 represents 10 and it is
00:47helpful to remember this as we are working the problem.
00:50Now that we have the numbers lined up correctly, let's represent these numbers using our place
00:54value blocks. To get 45, we need 4 10s blocks. 10, 20, 30, 40. And 5 1s blocks. 1, 2, 3,
01:064, 5. So here we have our 45 blocks and we know
01:10we need to subtract or take away 17 blocks. So let's start with subtracting the 1s.
01:17How many 1s do we need to subtract? We need to subtract 7 so let's do that. 1, 2, 3, 4,
01:265. Wait a minute, we can't take away 7 1s because we do not have 7 1s to take away.
01:34To solve this problem, we need to regroup. To regroup, we need to trade one of these
01:3910s blocks for 10 1s. Now we no longer have just 5 blocks, we have 15 blocks now. Now
01:48we can take away 7. How many 1s does that leave? Let's count and see. 1, 2, 3, 4, 5,
01:586, 7, 8. Let's put the 8 under the 1s place. Next we need to count the 10s place. But wait,
02:06we're supposed to have 4 10s blocks, but there are only 3. Why is that? Oh right, we
02:15had to trade a 10s block for 10 1s. Let's change this 4 to a 3. Now how many do we need
02:22to subtract from 3? Right, 1. 3 subtract 1 is 2, so 2 goes in the 10s place. So how many
02:31kids do we have left on the bus? 28. Great job!