Word Problems (Subtraction)

GenX-Education

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00:00Hello kids, welcome to the Dodgeball Gym. Today we will be learning about subtraction

00:07in word problems. We have some fun stuff to learn, so let's get started.

00:14Does anybody know what this sign means when we see it in a math problem?

00:19This sign means to subtract, and some other words for subtract are to take away or minus.

00:25Today we are working with word problems which are just stories about math. Here is our first

00:30word problem. It says, I have seven balloons and then two of them pop. How many balloons

00:36do I have now? Remember, it is good to read it a second time. I have seven balloons and

00:43then two of them pop. How many balloons do I have now?

00:49I believe that this math problem is asking us to take away because it said that they

00:53had seven balloons, but some of them popped. If a balloon pops, you no longer can play

00:58with that balloon, so they go away. So we will be taking two of them away just like

01:02it says in the word problem. I am going to start this with a circle drawing.

01:08Circle drawings are a great way to illustrate math stories or word problems. I am going

01:12to use seven circles to represent the seven balloons that we started with.

01:19Here are the seven balloons. The problem says that two of them popped. Do you think

01:23this means that it will take away two balloons or add two balloons?

01:29We will take away two balloons because they popped. I will put an X on two of these balloons

01:34to show that those two went away. Now the rest of the circles that do not have

01:40an X are the balloons that I have left. This is an awesome way to figure out the math problem.

01:46We need to write an equation to go along with this word problem.

01:51If you remember we had seven balloons total at the beginning, so we will write the total

01:55or seven first because this is how many we had before any of them popped.

02:00Then it told us that two of those balloons popped. We will now use the minus sign or

02:05the take away sign, which tells me that I am going to take away two of those balloons

02:08that popped. When we take the two balloons away, how many

02:13do we have left? Looking at the circles we started with seven

02:18and two popped and that leaves us with one, two, three, four, five. We have five balloons

02:24left. Great job kids, you guys are awesome! Let's quickly do a math mountain even though

02:31we have figured out the word problem. The really cool part about subtraction problems

02:36with math mountains is that usually we know the total. In this problem the total we started

02:41with is seven. This seven is at the top because it is the total we started with. I also know

02:47that of those seven balloons two of them popped. The two goes down as one of the partners.

02:53How many are left after the two balloons popped? The empty box is where the answer will go

03:00and it will be how many balloons are left after two balloons popped. We know it's five

03:04because we counted in our circle drawing and there are five balloons left. We can check

03:09our work with the math mountain because we know that two plus the other partner five

03:13equals seven which is the total. Awesome kids! Let's do another problem and see if you can

03:19do it. This time we are going to start by writing a math mountain, an equation and then

03:24a circle drawing to prove the answer. Here is another word problem. It says eight children

03:30are playing then five have to go home. How many are still playing? Let's read this one

03:35more time. Eight children are playing then five have to go home. How many are still playing?

03:44Let's start with a math mountain. I will give you a moment to do it yourself, okay? I can

03:52tell just by reading this problem that I have a total because eight children were playing

03:56and some had to go home. So our total is eight which goes at the top of the math mountain.

04:02We also know that five of the children had to go home. Five is one of the partners. We

04:08need to find out how many of those eight children are still playing after five went home. As

04:14we can see we have a total and we have one of our partners. We need to find out the other

04:18partner. With this information we can now write an equation. What is the equation? We

04:27have eight kids that were playing so we will write our total first because all good subtraction

04:31problems start with the total. Then I will put down the subtraction sign. Five of them

04:37had to go home so we put down five. And now there are still some playing but we do not

04:44know how many that is. What is eight take away five? The answer is three. Eight subtract

04:53five is three. Amazing job kids! To check our work we can use a circle drawing. Here

05:00we have eight circles to show the total amount of kids we started with. Now we subtract five

05:05circles because five of the kids went home. This leaves us with three circles which proves

05:11our answer. You guys did an awesome job! Thank you for helping me. We will see you next time.

05:18Goodbye!

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