Lesson Plan - Get It!
Imagine you work at a farmer's market. Every Saturday, your family sets up a booth and sells tomatoes, cucumbers, watermelons, squash, and onions.
At the end of the day, you have to figure out how many of each vegetable you have left.
For example, you started the day with 47 cucumbers. You look at the receipts and notice you sold 31 cucumbers. How many cucumbers do you have left over?
If you thought subtraction, you are correct!
We use subtraction because you start with a total number, take some away, and end with a smaller amount than you started with.
For this type of subtraction problem, set it up to look like this:
Place the starting total (47) on the top and subtract (31) below. Make sure that the numbers in the tens place and ones place line up.
Next, subtract the ones:
7 - 1 = 6
Then, subtract the tens:
4 - 3 = 1
And you have an answer: 16 cucumbers left over!
Now, let's look at the tomatoes.
You started the morning with 32 tomatoes. You sold 15.
- How many tomatoes do you have left over?
Let's set up the subtraction problem the same way. The total is the top number, and the number we are subtracting goes below. The numbers in the tens place and the ones place are lined up:
First, see if you can subtract the ones place:
2 - 5 ← You cannot take 5 away from 2.
We need to regroup!
When there are not enough ones to take away from, you have to borrow from the tens place. The borrowed group of ten will be regrouped and changed into ones.
Look at the number 32. In this number, there are 3 tens. In order to regroup, we will borrow a ten to regroup into ones:
When we borrow a ten to regroup, we no longer have 3 tens. Now, there are 2 tens:
Now, let's regroup that borrowed ten into ones:
We no longer have only 2 ones. Now we have 12 ones!
Let's see if we can subtract now! Start with the ones:
Because we regrouped a ten, there are now enough ones to take away 5!
Next, subtract the tens. Remember, there are only 2 tens now because we regrouped:
Great! Now we have an answer!
There are 17 tomatoes left over after the farmer's market.
Review what you just learned with Subtraction with Regrouping - Math Video for 2nd Grade from Math & Learning Videos 4 Kids:
- Ready to practice regrouping on your own?
Move on to the Got It? section to practice the steps to subtract with regrouping!