The following material has been developed by state and provincial organizations,
together with the Education Television Agency, together, to serve education.
Resuelvelo.
Computer Mental. The use of the computer mental to multiply.
How are you guys?
Oh, Uncle Ofe, we're almost done here.
Good, Claude. Remember when I taught you how to use the recorder?
Yes, yes.
What do you think? If you stay in charge for a while, I have to take care of that request.
Us? Are you sure, Mr. McFarley?
I wouldn't ask if I didn't have it.
It was a problem, Uncle Ofe. We can handle it.
Don't worry, it's not that terrible.
Three small pencils for painting, two with 95 each, and a
4.50 castellon game.
That would be 72.36.
Very good, here you go.
Thank you.
Thank you, guys.
I told you it wasn't that terrible.
Well, guys, see you next time.
Please, give me a quick answer. I'm in a hurry.
Of course, Mrs. Vado.
Three packages of nails, one with 19.
Six matches for curtains, three with center, five packages of sandpaper.
Oh, no, the light went out. The recorder won't work.
Oh, great. What do we do now?
Well, I guess we'll have to wait for the light to come back.
Look, I can't stay here all day. Can't you calculate how much I owe you?
Sure, of course, of course we can.
Okay, let's see.
Five packages of sandpaper, one with 90.
That would be five times zero is zero, and five times nine is 45, and five times one is five.
What would it give?
I can't believe it. They're having a problem.
You're right, Jess.
If your recorder is the most possible, you would be able to calculate the cost of sandpaper and its grades and its rings.
The recorder can be multiplied very quickly.
You don't always need a recorder, a calculator, or a pencil to be able to multiply.
Oh, no?
No. Sometimes what you need is to be able to multiply mentally with a very high ability.
And it's fun. There are all kinds of strategies to solve multiplication problems in that way.
You can bet that at this moment Gene and Claude would love to meet someone.
So how much does Claude give?
100. If you add everything, you give 50.
But it can't be, can it?
You guys are really bad.
Do you need help?
The recorder turned off.
We have a little problem trying to calculate what the lady owes.
Little?
We do what we can, Mrs. MacFarlane, but it's not easy.
If I were to tell you that my great-grandfather was here, I swear I couldn't help you.
Your great-great-grandfather? What was so special about him?
Didn't Claude tell you? That man was a legend in his time. And Claude had his name.
That's right. And my great-grandfather was really a phenomenon.
He was the fastest multiplier in the whole west.
Yes, you know, that man could multiply anything.
40 cents.
Thank you.
You're welcome.
Have a good day, Mr. Ferguson.
Okay, Jimmy, it's just making the inventory. We have to calculate what we have in the warehouse.
Oh, Mr. Claude, that won't take weeks.
You're silly, boy. Don't you know I'm the fastest multiplier in the whole west?
That's what people say, Mr. Perot.
Jorvencito, if you're going to be my employee, it's just that you learn something about multiplication.
Besides, it's better if you learn in case you come back.
Luke.
Do you have Luke?
Forget it. I don't want to scare you. Come here now.
Do you have Luke?
Luke, here you have the account. Let's see.
Snake oil.
18k.
Four bottles per house.
That's 72 bottles of snake oil.
Mr. Claude, that's fast.
Hey, old accountant, you're pretty passionate, aren't you?
You're right, man, and the truth is that it's not something you can't do.
The idea is to find easy numbers to remember.
So, we'll show you how Mr. Claude multiplied the bottles of snake oil.
This is a case for using the round-up strategy.
There were 18 oil boxes and four bottles per box.
But it's not easy to multiply four by 18 mentally.
So, Mr. Claude would answer 18 by 20 and multiply 4 by 20 is easy.
But remember that multiplication in mathematics is not an exact estimation.
So, Mr. Claude would draw the difference between the easy number and the real number.
And multiply it by 4.
Then he subtracted the total results and got 72 bottles of snake oil.
Of course, it's easier to do than to explain.
You're right.
And Mr. Claude's grandfather knew many other quick and simple strategies.
Now, let's go back to the old man.
Look, I'll show you the following so you can follow me.
These are pills for the liver.
19 boxes, 32 bottles per box.
Now, follow me.
Again, we're going to handle this a little bit differently than what we would do on paper.
In paper, you would first multiply the units.
Then the tens.
And so on and so forth.
But mentally it's easier to do it the other way around, you know?
I think so.
Listen carefully.
First we multiply 30 by 9.
That's 270.
Then the units of 2 by 9 is 18.
Then the other products are added and that's it.
Wow, Mr. Claude, that's great.
Mrs. Barrett, it's you.
I thought for a minute you could do it.
Who?
Nothing, nothing.
Tell me, how can I help you?
Well, I wanted to know if you would be interested in buying eggs regularly.
Is it possible, ma'am?
How many per month?
Well, we have 37 chickens.
The foxes ate three and each chicken puts about 20 eggs a month.
Well, young man, let's do this together.
It requires the rounding strategy again.
First we take an easy number.
So we round 37 by 40 and multiply 40 by 20.
It's 800.
Since we add 3 to 37 to round in 40, we have to multiply 3 by 20.
It's 60.
Now all we do is subtract 60 from 800, which gives us a total of 740 eggs.
Yes, that's right, ma'am.
Thank you, Mr. Claude.
It's a pleasure.
Mr. Claude, I'm getting a little dizzy.
Well, there's no reason not to do it.
Let's see here.
Less and less hard.
161 for the jar and three jars.
We'll try something different here.
We break 161 into two numbers for driving.
151 and 11.
Do you follow me?
Yes, yes.
Well, 150 times 3 is 450 and 11 times 3 is 33.
We add those two and it gives us 463 candies.
Did you understand?
Yes.
Let's see.
What are those lights?
122 for the jar.
Four jars.
Here we have an interesting situation, Kimmy.
I can think of two ways to solve it.
Two?
Yes.
Sometimes I can think of three, four, five or more methods to solve multiplication problems.
But for those candies, here we have one.
We take 122 into two simple numbers.
One hundred and twenty-two.
We multiply each one by four.
We take a result and it gives us a total of 488 candies.
When we do the initial multiplication, we write down the numbers involved for a moment.
Then you choose the one that makes it easier for you.
It will be faster for you too.
And remember that you will improve with practice.
Now we will meet someone with a lot of practice.
We are in the kitchen of the economist who provided the food for the team during the filming of this program.
Do you think this needs more flour?
Yes.
A lot?
Around a cup.
Okay.
For an economist to make a mistake means that he has enough food or that you wasted it.
How many times did you make those mistakes?
Five.
We are serving food for twenty people today.
I know that with a cup of rice they eat four people.
So four times five cups is twenty people.
And the list was here at ten thirty.
They told us that we have to be there at twelve because the team has to eat at twelve thirty.
We must find out exactly where it is because if it takes us half an hour to get there,
it means that to get there at twelve we have to leave at eleven thirty, which means that we have to have lunch ready for eleven and fifteen hours.
Exactly.
Today we had lunch with fish so I calculated half a pound per person.
And for twenty people to eat I knew that I had to buy ten pounds of fish.
Buy one more for one.
For twenty people we spent one hundred and fifty pesos.
I have to do these calculations all the time.
If it wasn't very practical for me to use a pencil and paper or a calculator, it's much better for me.
I don't think we have many options in life.
I think you have to learn to do multiple calculations.
Damn, I'm going to be fast, Mr. Claude.
I told you.
So there you are, Luke.
Look Claude, you still think you're so fast, huh?
I guess you came back with a new calculator.
That's right, old accountant.
I still have what I need to have.
Well, we'll see.
What is it about?
About these cookies.
Exactly.
I have 1,062 cookies in this box and three boxes like this.
How many cookies are there in total?
This time it's the boy's turn.
What is it about?
Who said anything about the kid?
Look, you have 15 seconds or you and the old man die.
I'm going.
Uh, we'll be right back.
Your time is running, son.
4,278 cookies.
Oh, you're right.
Well, you can keep the cookies.
We can keep the crackers.
That fast calculator didn't work.
Oh, Mr. Claude, you taught me.
That's the story of my great-grandfather.
The fastest multiplier in the whole west.
That's right, that's right.
Except for the employee, of course.
Well, it's all very interesting,
but I can't wait all day here until the light comes back.
Don't worry, ma'am.
Kim and I can handle it without the calculator.
Right.
Let's see.
Yes.
Three packs of steel soup, one with twenty-six, the package.
Uh, uh, uh.
3,78.
Now it's better.
Yes.
Six packages of snacks for four, three with fifteen, each.
Hey, the regulator, it's working again.
Really?
Really.
Oh, it's working.
I was just starting to like it.
Me too.
Resolve it.
This program was supported in part by the National Science Foundation
and was produced by Judy Elkman.
Under the supervision of the Agency for Instructional Personality, AIT.