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Berndt-G3-9-15-04

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I dont want to know the answer yet. I want to know the thinking first. Easy to tell the answer. I want to think about it. Britney, excuse me, I want your eyes up here. Mercedes, up here You need to be participating to understand. Ok. So lets go back to what number six says Professor Peabody took a sample of 16 beans from a container Thats how I got this 16. That's his total. He recorded 2 for limas, 9 for pintos, but he forgot to record how many for navies before he put them all back in the cup? How do I figure this out? We know this is the number set that can tell us the answer. What is my strategy for thinking about it? Arthur! Well, you have 2 and 9 equals 11. So now Arthur is thinking I know this much is 11. Now you count up all the way to 16. And tell your number how many did you get all the way to 16. So you are using the counting up strategy? So when you count up from 11 to 16 how many is that? Umm,.. 5. Did anybody have a different way to do this one? Yes, Nicole. 5 + 12 + 2 equals 22 5 plus 12 plus 2? Are you on problem 6? No. Okay. Let's get to 6. Say that one when we get to that. Problem 9. You guys solved 6? Ok. Listen up. Emma. I know we had to pick a number. So I knew that... that 2 and 5 equals 7 and 7 and 9 equals 16. So I picked the 5. Okay. That should sustain. Wait a minute, 2.. Say it again. You get 2 and 5 with 7. and because you learned that factorally you knew in your head that 7 an 9 equals 16? No.. I said.. Yeah. Okay. You already memorized that 7 plus 9 is 16. So then you said, if I have got 2 from this 7, then I know I am missing 5. Good thinking! Would a picture help you with this one? Remember when you had to draw our lab picture, Krystin? The lab picture for this might look like okay, which beans are these? These are my limas. Then I do one, two, three, four, five, six, seven, eight nine. These are my pintos, right? But I don't know what's in this last group called navies. What I think of this is, okay, here's the whole spoonful. Here's all the beans that he took out of the sample first. Two of them went to this pile. So I know there are 16 beans here, right? So 16 take away 2 so far So 16 take away 2 is - There's 14 beans still here. But now, I take the pintos out. So now I have 14 left and I take out the 9 for the pinto What's left in this pile? 14 take away 9? 5 again, isn't it? So now I know the answer is 5. So I really could think of this as subtraction. couldn't I? Bart! But that doesn't make sense because when you take the spoon out you don't really know how many you have in there. When you first do, you are exactly right Bart but when I read the question you don't really know. Yes, Matt. Well you can times it. How do you times it, Matt? 2 times 8 equals 16, minus 11 equals 5. Wait a minute, so you want to go 2 times 8 equals 16 16 minus 11 equals 5? I don't see how that matches my data You do have a correct calculation 2 times 8 is 16 and 16 take away 11 is 5. 5 is the answer. But I don't understand this part. Why do you think we should multiply? Does that really fit what this problem is telling you? No, but it would be faster. Multiplication is faster when it is in a problem. Do we have 2 groups of 8 anywhere in our problem? No. That's why it doesn't fit. But in this part, how does the subtraction part fit? Taylor and Luke, can you help us figure that out? Subtraction fits this. See, you tend to stop the wiggling back there or kicking or whatever else you are doing. Chris, you haven't helped us do any thinking yet. I need you to pay attention. Go ahead, Jones. Let me know how the subtraction fits. Subtraction fits, uh, by if you,... if you have like 16 ... 16 in one spoonful Dump it out and count till 16. Then if you have, like, How did we get this 11? How does Matt's "take away 11 number set" fit? Everyone should be able to look up here and figure it out It does fit. I'm telling you. Yes. It does. It works. You tell me how. Amanda. Where did Matt get 11? It jumping up and jumping out after you guys look at the screen. The arrow head says 11 right? Where did that 11 come from? Tell me 2 numbers. Aaron, settle down and give people a chance to think. She sees the 11 here. Are you with her? Yes! She sees this. How did we get this? Where did that come from? Bart. From pintos and navies. Does it have the pintos and the navy together, the 2 plus 9? No, its the lima. So over here, in our drawing, isn't that this part together? Yes! 2 for lima and 9 for pinto. So if I take away the ones I know So I know theres 2 and 9 So taking away 11 beans from the 16 That tells me how many are left in this pile. Joe, you see now why that works? I don't think so. You were whispering with Krystin. Ah. Well this works and then we don't listen. Did we do question 4? No. We did not. 4 students are playing a game of, oops, this is 4a playing a game of turnover. The target number is 25. Martha turned over an eight, Stephanie turned, excuse me, Stephen turned over a five. Then Christine turned over a three. What is the sum? Quickly tell me what to do Every hand should be up. Some of us are just more busy wiggling instead of thinking about Math. Its very disappointing. Nathan, look at the book. Matt, put the book over next to where Nathan can see it. Emily, quick. I forgot. You forgot, aw. What do I add? Tell me what to do. You add 8 plus 5 plus 3 8 for Markus, 5 for Steven plus 3 for Christine, right? Ok. What do they have so far? Anne. 16. 16. 8 plus 5 is 13 and 3 more, we have 16 so far. Excuse me, b now says Now its Marciella's turn. What card does she need to turn over to win the game? Now, remember there are no tens. Its all 0 through 9. What does she need? Now we know they have 16 so far. What are the going to end up at? What's their target number? Twenty five. So is this the one where we have to say what do we need to get to 25? Arthur. 9. How did you get that? Because 16 plus 4 equals 20. and 20 plus 5 equals 25 So he's saying that 16 plus 4 equals 20 So I know I need at least 4 and then I want to go 20 up to 25, right? So I know that is 5. So then you add the 4 and the 5 equals 9 and you got 26. 25! Ya. 25. He counted it up to the even 20 added on the 5 more that he needed so then he found out 4 plus 5 is a 9 So the card is a 9. Could you do this by subtraction? Yes. How? Chris. We are trying to figure out question b by subtracting Ok. Nobody can figure out the subtraction way? Emma again, tell it out Emma. 25 take away 16 You know the target number is 25 You know the first 3 cards added up to 16 Right? So if the take away the card that we already got to Eleven? Wait a minute. If I have only 5 ones, 5 bits can I take 6 of them away? I have 5. How can I give you 6? Don't I have to do some regrouping? Its nineteen. Ah. What's nineteen? Wait a minute. Where am I getting some more to make this? I need some more bits here. Don't I have to do some regrouping? What can I regroup? The two. The two. Oh. Its not 2, its two tens. two skinnys So if I exchange one of those skinnys how many skinnys are we left? One. Now that gives me 10 more bits plus the 5 that we have here. How many bits? fifteen. Fifteen take away six is 9. One skinny take away one skinny - No skinnys. So did we get 9 again? Okay!

Video Details

Duration: 1 hour and 28 seconds
Country: United States
Language: English
Genre: None
Views: 53
Posted by: shasi1711 on Oct 19, 2009

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