Mr. Madden

Fractions: What are Fractions: What are they?they?

Fractions: What are Fractions: What are they?they?

We’ll learn about:Fractions of whole numb

ersMixed Numbers

Mr. Madden

Let’s understand a fractionLet’s understand a fraction

¾ 2

1

3

The top number (numerator) tells HOW MANY parts of the whole object we have

The bottom number (denominator) tells HOW MANY parts the whole object is divided into.

Mr. Madden

Let’s check this outLet’s check this out

56

Pretend you are at a party and you get to have5/6 of a tasty pizza. Which picture shows how many parts it should be divided into?

Mr. Madden

HOT STUFF !!!HOT STUFF !!!

56

Yes, the bottom number (denominator) tells us itIs divided into 6 parts.

Mr. Madden

HOT STUFF !!!HOT STUFF !!!

56

Now, how many parts do you get? Click on the arrow.

? ?

Mr. Madden

HOT Pepperonis !!!HOT Pepperonis !!!

56

The top number (numerator) tells us how many we get.

5

On to Bigger and Better

Mr. Madden

Oh mushrooms, no, try again !!!

Oh mushrooms, no, try again !!!

56

The top number (numerator) tells us how many parts we get.

5 NO!

Try again

Mr. Madden

Whoops, darn, shucks…Whoops, darn, shucks…

The bottom number (denominator) tells us itis divided into 6 parts.

Hint: Divided and Denominator both start with D, andso does the word Down, like Down under.

56

Try Again

Mr. Madden

Try this oneTry this one

710

Mr. Madden

Finding fractions of whole numbersFinding fractions of whole numbers

To find a fraction of a whole number, first divide the number into equal parts.

A class predicts that ¾ of 88 piano keys are ivory.

First divide the 88 keys into how many equal parts?

43 12

Mr. Madden

Nope, try again!Nope, try again!

Go again

Mr. Madden

Bingo! 4 is correct!Okay! Let’s move on.

Mr. Madden

Now that you’ve got 88 keys divided into 4 equal groups, you need to find how many keys will belong to each group.

Will there be:

40

2292

Mr. Madden

Yep, because 88 divided four equal ways is 22.

Yep, because 88 divided four equal ways is 22.

Don’t stop now!

Mr. Madden

Okay, now we know that if we take the 88 keys and break them up into 4 equal groups, we’ll have 4 groups of 22 keys. But if we want to find ¾ of 88 keys, howmany groups do we consider?

3 412

Mr. Madden

Nicely done!3 equal parts

Now what?

Mr. Madden

The answer to “What is ¾ of 88?” is the total number of keys in the 3 groups of 22. What’s the total?

66 6.66

Mr. Madden

Absolutely right, because 22 multiplied by 3 is 66.

Good work!

What about Mixed Numbers?

Mr. Madden

Mixed NumbersMixed Numbers

When a part is more than a whole, you can describe it two ways:

Fraction

If the pizza is divided into six equal pieces, then each piece is 1/6 of the

pizza, right? Right!

Check it out!

Mr. Madden

Well, what if you ordered 7 slices, or pieces? How many pizzas would you have now?

6/6, or one whole 1/6, or one-sixth

and

7/6

21 1/6

Mr. Madden

Improper FractionsImproper FractionsNicely done!

Yes, if you have a total of seven pieces of pizza, and each is 1/6 of the whole, then you have 7/6

pizzas!

But doesn’t it look strange, or improper, to have the numerator (7) larger than

the denominator (6)?

So what do we do?

Mr. Madden

Mixed NumbersMixed Numbers

Well, we have a whole pizza (1) and a fraction of another pizza (1/6). Let’s put them together.

Now we have one and one-sixth pizzas.

We write this 1 1/6.

Try this!

Mr. Madden

How many red squares are shown?How many red squares are shown?

3 3 1/4 4

Mr. Madden

You got it square on the target!

Since three whole squares (3), and one-fourth (1/4) of another square are red, then there are

3 + 1/4 red squares, but we don’t use

the “+” sign. Just write “3 1/4.”

Give it a shot

Mr. Madden

Your big cousin, Ernie, and you have a pizzafest.You buy 7 pizzas, and eat for hours. Below is what you didn’t eat.

How much pizza is left?

17/6 2 5/6 6/17

Mr. Madden

I’m surprised you can move!

Yep! You and Ernie still have 17/6, or 2 5/6 pizzas left to chow on.

(Maybe you should save them for breakfast.)(Maybe you should save them for breakfast.)

Good job!!