Project Math Access DVD 02 - Abacus- Part 17
Transcript Start
Audio Description: Part seventeen; abacus secrets method; subtraction; example two.
TEACHER: Let's try a couple more with ones. I think we need a little bit more review. Let's do 35...
PARAS: You know the other tricky, the other Secret‘s more tricky.
TEACHER: When you have to, you have to know which Secret to use. And you know that because you can't use the other Secret. First of all, I didn‘t give you the problem, Mr. I Work Ahead. 35-11. Say that louder Joey.
JOEY: Don't have 1.
TEACHER: Okay, so what do you do?
JOEY: 24
TEACHER: What was the Secret you used?
JOEY: Clear 5, set 4.
TEACHER: Good. Did you get anything over there, Paras?
PARAS: 24
TEACHER: 24. Alright, I'm going to have Joey check it. 35 -11.
CALCULATOR: 3 5
(sneeze) TEACHER: Bless you, Paras. Minus is above the plus.
CALCULATOR: minus 1 1
CALCULATOR: equal 24
TEACHER: Is that what you got?
STUDENTS: Yes.
TEACHER: Yes, you guys are getting good. Think you about got this Secret down. One more and then we're going to go on to twos. Ready?
STUDENTS: Yeah.
TEACHER: Oh, let's do 45...
TEACHER: got it Paras?
PARAS: Yep.
TEACHER: 45 -11.
Okay, what‘d you get, Paras?
PARAS: 34
TEACHER: What‘d you get, Joey?
JOEY: 34
TEACHER: What was the Secret you used, Paras?
PARAS: Clear 4, set 5.
TEACHER: What did you use, Joey?
JOEY: Clear 4, set 5.
TEACHER: Oh, you guys both got it. Come on, fives. Whew! Alright, let‘s do the twos and then we're going to stop for today. Okay? You guys have been working hard for 42 minutes. Sound good?
STUDENTS: Yeah.
TEACHER: Alright, let‘s take a look at your Subtraction Secrets that are on your left.
JOEY: Clear 1, sets.
TEACHER: Alright, you already know it? What‘s the Secret for subtracting 2, Joey?
JOEY: To subtract 2, see 3, clear 5.
TEACHER: To subtract 2, clear 1 left, sets. Did Duxbury do some funny things? And what‘s the other Secret for adding 2, excuse me, subtracting 2, Paras?
PARAS: To subtract 2...
TEACHER: We already said to subtract 2, clear 1 left, set 8. Now what‘s the other one?
PARAS: To subtract 2, set 3, clear 5.
TEACHER: Very good. I need you to clear your abacus and we're going to try some examples.
The first Secret we're going to use is: to subtract 2, clear 1 left, set 8.
I'm going to give you the problems: 20, I need you to put your abacus down on the table, 20 - 2. We need to go to our tens columns and subtract 2 Do we have 2?
STUDENT: No.
TEACHER: No, so what is the Secret we're going to use?
STUDENT: CIear 1 left, sets.
TEACHER: CIear 1 left, sets. What'd you get?
JOEY: 18
TEACHER: Is that what you got, Paras?
PARAS: 18
TEACHER: Okay, let's check it in our head. is 20 - 2, 18?
STUDENTS: Yes.
TEACHER: Yes. Alright, clear. 70, I need you to set 70 for me. 70-2. We don't have 2, so we're going to... clear 1 left, set 8. What‘d you get?
PARAS: 68
TEACHER: Is 70 - 2, 68?
PARAS: Yeah.
TEACHER: Are you sure? Got that in you head? Can you do that one in your head?
PARAS: Yeah.
TEACHER: Okay, alright, we're going to try two more with the other Secret for subtracting 2. What was that other Secret for subtracting 2 again, Joey?
JOEY: see...
TEACHER: No, set...
JOEY: because Duxbury made it...
TEACHER: Duxbury made a mistake, so we're going to figure out what it is. We're doing subtract 2; the first part is set...
Did you find it, Paras or do you know it?
PARAS: Set 3, clear 5.
TEACHER: Oh, smarty over here knows it. Set 3, clear 5. Set 3, clear 5. Here we go.
25...
Audio Description: Joey reads from the sheet of secrets.
TEACHER: That is not setting 25. I will set 25. Thank you.
25-2. Use your Secret. What Secret did you use, Joey?
JOEY: 23 is the answer.
TEACHER: Well, I want to know the Secret though. What's the Secret?
JOEY: Clear 5, set 3.
TEACHER: Clear 5, set 3. What'd you get, Paras?
PARAS: 23
TEACHER: Great. Alright, is 25 - 2, 23?
PARAS: Yeah.
TEACHER: Yeah, you can check that in your head. We don't have to check it on a calculator.
TEACHER: Okay, we've got one more. Think you can you make it? I'm going to make this one a little harder, so you can't check it in your head. 45 - 12. Go to your ones column, subtract 10. Excuse me, your tens column and subtract 10. Go to your ones column; we want to subtract 2. We don't have 2, so we subtract...? What's the Secret, Joey?
JOEY: 3, 5
TEACHER: What? What about 5?
JOEY: Subtract 5
TEACHER: And set?
JOEY: Set 3.
TEACHER: What did you get for your answer?
JOEY: 33
TEACHER: Why'd you clear it so fast? Speedy over here, I didn't see what your answer was. What did you get, Paras?
PARAS: 33
TEACHER: Okay and you didn't clear it, thank you. Alright, you guys did a nice job on this. What do you think about the Secrets, Joe?
JOEY: They're hard.
TEACHER: They're hard. Which is harder, subtraction or addition?
JOEY: Subtraction.
TEACHER: Yes, I bet it is.