Project Math Access DVD 02 - Abacus- Part 16
Transcript Start
Audio Description: Part sixteen; abacus secrets method; subtraction; example one.
TEACHER: Okay listen to your directions. You should have your abacus paper in your braillewriter, the abacus on your right, on your right Joey. Thank you, on your right.
And we're going to review Subtraction Secrets before we begin. Now this is kind of new, so we're going to review these one by one. Why, why, why do we have to use Subtraction Secrets? You don't know?
JOEY: to go down
TEACHER: To go down? What do you think Paras?
PARAS: Because it‘s easier to do.
TEACHER: It‘s easier to do? You guys are close.
JOEY: I know.
TEACHER: Okay smarty, let's hear it.
JOEY: It's...
TEACHER: Do you need to think? Do some hand presses because you're kind of...
JOEY: I know, it‘s...
TEACHER: I will tell you.
JOEY: I will tell you.
TEACHER: Okay, it is because...
JOEY: It is because...
TEACHER: you do not have enough beads to clear.
JOEY: you do not have enough beads to clear.
TEACHER: Alright, hand presses, hand presses. You're doing great, you're doing great. How about some chair push-ups for me too?
JOEY: No
TEACHER: Yeah, I think you're getting silly. Okay, I'm going to give you a copy of the Subtraction Secrets and we're going to review. We're just going to start with 1, first of all. We want to clear 1, but we don't have 1. What in the world are we going to do? What in the world are we going to do? Let's review. Joey, read to me Secret number 1.
JOEY: To subtract 1,...
TEACHER: I need you to put your braille paper on your desk, two hands on your reading.
JOEY: clear 1 left, set 9 right.
TEACHER: To subtract 1, clear 1 left, set 9 right. What's the other Secret for subtracting 1, Paras?
PARAS: To subtract 1, set 4, clear 5.
TEACHER: Set 4, clear 5. Okay, get those in your brain. Got it?
TEACHER: Got it? Okay, we're going to try the first one. Take a look at problem number 1. Your abacus should be on your right.
PARAS: 20 - 1
TEACHER: 20 - 1, now these are real easy, so you should be able to get them on your abacus. Set 20 on your abacus, set 20 on your abacus still. I will set 20.
We want to subtract 1; what column do we want to subtract that from, Paras?
PARAS: Clear the 10?
TEACHER: Okay, listen carefully, 20 - 1. We want to subtract 1. Are we supposed to subtract that from our tens column or our ones column, Joey?
JOEY: ones
TEACHER: Okay, so set 20. We want to clear or take away 1 from the ones column. We do not have 1,...
heIIo Secrets! Can you say that louder Paras?
PARAS: CIear 1 left, set 9.
TEACHER: Alright, what'd you get?
JOEY: 19
TEACHER: Is that what you got Paras?
PARAS: Yeah
TEACHER: Okay, now this we can check in our head. Is 20 -1, 19?
PARAS: Yes
TEACHER: Yes, that one we can check in our head; we don't have to check that on the calculator. Alright, I need you to put your answer down please. 20 -1 is 19, you got that right.
Okay, what's the next one? We just did 20 - 1, what's number 2 say?
JOEY: 80 - 1
TEACHER: Okay, here's your abacus. 80, set 80 for me Paras. We're going down, we're going vertically, we're going up and down, okay?
PARAS: 80 - 1
TEACHER: Alright, so you need to set 80.
JOEY: I got that in a quick time.
TEACHER: You got it already? Oh, a smarty pants over here. Oh, you're having a hard time too; it's a bad paper day, huh? There we go, 80 - 1. Okay, so set that 80. Want to subtract 1, don't have 1.
PARAS: CIear 1 left, set 9.
TEACHER: What'd you get?
PARAS: 79
TEACHER: Is 80 - 1, 79?
PARAS: Yeah
TEACHER: Yeah, you can check that in your head. You guys got that right. What was the Secret Joey?
JOEY: 79
TEACHER: That wasn't the Secret, that's the answer. [laughter]
JOEY: CIear 1 left, set 9.
TEACHER: Clear 1 left, set 9 to the right, very good. Alright, we're going to try one now using the other Secret for 1. Each number has two Secrets except for what, Paras?
PARAS: 5
TEACHER: Except for 5. The other Secret for adding 1 is what? What's the other Secret for adding 1? Look on your Subtraction Secrets to your left. What Paras?
PARAS: Set 4, clear 5.
TEACHER: Set 4, clear 5. We're going to go to the problem that says 25 -11. Find that on your paper. Excuse me; it's towards the bottom. Actually it's number 13; it's in your right-hand column.
TEACHER: 25 - 11
PARAS: Here?
TEACHER: Yep.
TEACHER: We're going to take yours out too. Baaaaad paper day.
25 -11, are we using two hands? Alright, so you need to set 25 for me please.
PARAS: 25
TEACHER: Okay. Got that Paras? Now Paras I want you to talk through it, talk through it when you do it this time, - 11.
PARAS: Set 4, clear 5
TEACHER: What'd you get Paras? Are you going to try it again?
PARAS: Yeah
TEACHER: Okay, why don't you clear and try it again. And I want you to talk your way through it, okay?
I don't hear any talking.
PARAS: 25, cIear 1 left, set 9
TEACHER: You're using the other Secret this time, that's what's tricking you, okay? Let's work through it together. 25, set 25.
PARAS: 25
TEACHER: - 11, first go to your tens column and subtract 10. Go to your ones column, we do not have 1 to subtract, so we're going to use the Secret which is set 4, clear...?
JOEY: 5
TEACHER: 5, what did you get Paras?
PARAS: Um, 14.
TEACHER: 14, okay. This next one, I want you to work on it quietly, and Joey I want you to talk through it. I want you to talk like you always do, okay? When you're using the abacus, talk your way through it. I want to hear you telling me what you're doing.
JOEY: Which number are we on?
TEACHER: We're going to do 65 - 1.
TEACHER: It's 65 - 1, Paras.
JOEY: 65, I said 65, I clear that 1
JOEY: I can't clear that 1, so,... yes I can.
TEACHER: You're using the other Secret this time.
JOEY: 64
TEACHER: Let's walk through this. You're using the other Secret, which is set 4, clear 5. Try it again, 65 - 1.
JOEY: 64
TEACHER: Is 65 - 1, 64?
JOEY: 54
TEACHER: Pardon me?
JOEY: 54
TEACHER: 65 -1 is 54?
JOEY: 64
TEACHER: Thank you.
TEACHER: Thank you. Let's try another one. Let's do 25, actually, let's do 75, 75.
JOEY: 75
TEACHER: umhum
JOEY: 75
TEACHER: You don't have 75 set, bud, 75.
TEACHER: - 1, use your Secret in your ones column. What's your Secret, Joey? I didn't hear you.
JOEY: Clear 5, set 4.
TEACHER: Good. What did you get, Paras?
PARAS: 64
TEACHER: You mean 74?
PARAS: Yeah
TEACHER: 74, alright, give me five. Alright, give me five, Paras.