Representing 2-step word problems

0:00- [Instructor] We're told a bakery sold 144 cookies, 308 cupcakes, and 180 loaves of bread over the weekend. How many items did the bakery sell all together? So what we need to do is pick the strip diagram that would actually help us answer this question. So pause this video and think about which of these three you would pick that would actually help us answer the question of how many items did the bakery sell all together?

0:27All right, now let's work through this together. So they're giving us the different items. So we have cookies, we have cupcakes. Lemme do that in a different color. I'll do this in blue. We have the cupcakes and then we have the loaves of bread, and then we have the loaves of bread.

0:49Now if we want 'em all together, we want to add them up, so I wanna see a strip diagram that adds these together. So let's see. This first one, it looks like it's adding 144 and 308, the cookies and the cupcakes, but then it has the loaves of bread over here. So the loaves of bread plus something else is going to be the same as the cookies and the cupcakes.

1:11That doesn't make sense. Now, choice B here, it looks like it's got the cookies here, 144, it's got the cupcakes, 308, it has 180 loaves of bread. They're using different colors than I used and we have one strip after the other and they're all being added together for this total amount right over here.

1:30So that makes sense. You would add these together to get the total amount. So I like this choice. Now let's just make sure this one doesn't make sense. This one is saying if I have 180 and 144 and something else, what is the something else to get to 308? We're not trying to get to 308.

1:45308 is the number of cupcakes. We're trying to get the total. So once again, we want to go with choice B. Let's do another example here. So now we are told that Diego has $700 in his bank account. He spent $186 shopping. The next day he deposited $45, that means putting money back into the bank account.

2:09How much money is in Diego's bank account now? So which of these number lines actually show that or would be helpful for figuring out how much is in his bank account now? So let's look at these choices. This first one, actually, all of them start with 700. They go from zero to 700, we see that in all of the choices.

2:26Now in this first one, we go from zero to 700 and then it looks like we are then taking back 186, which actually makes sense. So lemme color code it. So the $700 in the bank account, it looks like they all show that. It goes from zero to 700 right over there. Spent $186, so if you're spending it, that would go out of the bank account, so that should decrease the number.

2:48So this purple line, it looks like we are subtracting 186 here, looks like we're subtracting 186 here. This one doesn't make sense. It looks like we're adding another 186, so I'm going to rule this one out already. And then after we subtract 186, this first choice is then looks like it's subtracting another amount.

3:08Let's call that, maybe that's the 45 in green right over here. Lemme put that in the same color. So maybe that's the 45. But if you're depositing $45, that should increase your bank account, so you shouldn't go down another 45, you shouldn't subtract 45, so I don't like this one.

3:24Choice B looks right. We have 700, we took out 186 spending it, and then from that point, we add back another 45, so I am liking choice B.