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 lesson in the new math. tonight we're going to cover subtraction. is the first room I've worked for
a while that didn't have a blackboard so we will 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 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 right answer here's how they do it now.

You can't take from two,
Two is less three,
So you look at the four in the place.
Now that's four 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 that

Now instead of four in the tens
got three,
'cause you one,
is to say, ten, to the two,
But you can't take seven three,
So you in the hundreds place.

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

Well, six actually.
the is the important thing.

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

Everybody get
Not bad for the day!

for new math,
New-hoo-hoo-math,
It do you a bit of good to review math.
so simple,
So simple,
only a child 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 eight is just base ten really
if you're missing two fingers. shall we a go at it? hang on.

You take three from two,
Two is less three,
So you look at the four in the place.
Now really four eights,
So you it three eights,
Regroup, and you change an to eight ones,
And you add to the two,
And you get base eight,
Which is ten ten,
And you take 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 can't take from three,
So you at the sixty-fours.

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

From the three you 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 with two,
And you away one from two,
And leaves...?

Now, not always see the same hands.
One, right!
Whoever got one can stay the show and clean the erasers.

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

Come back tomorrow night. gonna do fractions.