Luyện nghe bài hát New Math

Some of you who have small children may have perhaps been put in the embarrassing position of being unable to do your child's arithmetic homework because of the current 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 going to cover subtraction. this is the first room I've worked for
a while that didn't have a blackboard so we will have to make do 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 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 right answer here's how they do it now.

You can't take three two,
Two is less three,
So you look at the in the tens place.
Now really four tens,
So you it three 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 of four in the tens place
got three,
'cause you one,
is to say, ten, to the two,
But you can't take from three,
So you in the hundreds place.

From the you then use one
To ten ones...
(and you know why four plus one
Plus ten is fourteen one?
addition is commutative, right.)
And so you thirteen 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 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 eight. but don't panic. base eight is just like base ten really
if you're two fingers. shall we have a go at it? hang on.

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

Now instead of four in the place
got three,
'cause you one,
is to say, eight, to the two,
But you can't seven from three,
So you at the sixty-fours.

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

the three you then use one
To make ones,
And you add those to the three,
And you get base eight,
Or, in words,
In ten you have eleven,
And you away seven,
And seven eleven is four.
Now go to the sixty-fours,
And you're with two,
And you take away one 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 good to math.
so simple,
So simple,
That only a can do it!

Come back tomorrow night. gonna do fractions.