Fractions are parts of a whole or parts of a set.
Many things can be divided into fractions. A
favorite food can be divided into equal size pieces or fractions. A
round pizza is a great example.
Let's say I bought a pizza to share with my friend.
Each of us is very hungry, so we decide to divide the pizza evenly.
I would cut down the middle of the pizza so that each of us could
have half of the pizza.
I want to show a half in fraction form, so I would
write 1/2.
The numerator in a fraction is the number that
show me how much of something I have. In my example of the pizza,
I have one whole pizza. The numerator is always the top number in
the fraction.
The denominator in a fraction is always the bottom
number. It is the number that tells me how many pieces I need of the
top number. Because I am sharing my pizza with my friend, I need 2
pieces. I need one piece for my friend and one for me. Each of
us will have "one half" or 1/2 of the pizza.
The line between the numerator and the denominator
is called the fraction bar or division bar.
Imagine a whole pizza. Now imagine the friend
you will share this pizza with. In your mind, cut the pizza into
2 equal parts. One half is for your friend and the other half is
for you. You have created a fraction. The fraction is "one
half" or 1/2.
Let's change this "mind movie" a little. On
another night, you decide to have pizza again. This time you have
2 friends to help you eat your pizza. Will you be able to eat 1/2
(one half) of the pizza this times? Cutting the pizza in half (2 equal
parts) will not give all three of you equal parts of the pizza. The
pizza now needs to be cut into three equal parts.
You have one pizza - 1
(numerator)
3 hungry people
3 (denominator)
Your new fraction is 1/3 or "one third". The
pizza will have to be cut into three equal parts. Hopefully, you're
not as hungry on this night. Although all three of you have an equal
size piece, your piece is smaller than 1/2 or "one half" of the pizza that
you had the other night.
The next time you decide to have pizza, still another
friend decides to join you. One pizza needs to be equally divided
between four people.
What will be your numerator? What will be your
denominator? How can you cut a pizza into 4 equal parts to feed 4 hungry
people? you have one pizza and 4 people to feed.
Remember that the numerator tells how many you have.
The denominator tells how many you need to divide by. One pizza
needs to be divided into 4 equal parts.
One pizza - 1-(numerator)
4 hungry
people 4 (denominator)
You're new fraction is 1/4 or "one fourth" Isn't
this fun? Aren't you hungry? Come to think of it, I am too!
Let's get a pizza!
It's time for some more practice!
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Last Modified on May11, 2003
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