Luyện nghe bài hát New Math

Some of you who have small children may perhaps been put in the embarrassing position of being unable to do your child's arithmetic homework because of the current revolution in mathematics teaching known as the new math.

So as a public service here tonight I thought I would offer a brief in the new math. tonight we're going to cover subtraction. this is the first room I've worked for
a while that didn't have a so we will have to make do with more primitive visual aids, as they say in the "Ed biz." consider the following subtraction problem, which I will put up here 342 - 173.

Now remember how we used to do that. three from two is nine; carry the one, and if you're under 35 or went to a private school you say seven from three is six, but if you're over 35 and went to public school you say eight from four is six; carry the one so we have 169, but in the new approach, as you know, the important thing is to understand what you're doing rather than to get the answer here's how they do it now.

You can't take three two,
Two is less three,
So you at the four in the tens place.
Now that's really tens,
So you make it tens,
Regroup, and you a ten to ten ones,
And you add to the two and get twelve,
And you away three, that's nine.
Is clear?

Now of four in the tens place
got three,
'cause you one,
is to say, ten, to the two,
But you take seven from three,
So you look in the place.

From the you then use one
To ten ones...
(and you know why plus minus one
ten is fourteen minus one?
'cause is commutative, right.)
And so you have tens,
And you away seven,
And leaves five...

Well, six actually.
the is the important thing.

Now go back to the place,
And you're with two.
And you take away one two,
And leaves...?

Everybody get
Not bad for the day!

for new math,
New-hoo-hoo-math,
It won't do you a bit of good to math.
so simple,
So simple,
That only a can do it!
Now that actually is not the answer that I had in mind, because the book that I got this problem out of wants you to do it in base eight. but don't panic. base is just like base ten really
if you're missing two fingers. shall we a go at it? hang on.

You can't take three two,
Two is than three,
So you look at the in the eights place.
Now that's really eights,
So you make it eights,
Regroup, and you change an eight to ones,
And you add to the two,
And you get one-two eight,
is ten base ten,
And you away three, that's seven.

Now instead of four in the eights
got three,
'cause you one,
is to say, eight, to the two,
But you take seven from three,
So you at the sixty-fours.

"sixty-four? how did sixty-four get into it? " I you cry.
Well, sixty-four is squared, don't you see?
(well, you ask a silly question, and you get a answer.)

the three you then use one
To eight ones,
And you add those to the three,
And you get base eight,
Or, in words,
In base ten you eleven,
And you away seven,
And from eleven is four.
Now go to the sixty-fours,
And you're left two,
And you away one from two,
And leaves...?

Now, let's not always see the hands.
One, right!
got one can stay after the show and clean the erasers.

for new math,
New-hoo-hoo-math,
It won't do you a bit of to review math.
so simple,
So simple,
That only a can do it!

back tomorrow night. we're gonna do fractions.