Transcript Fractions - amerischoolsmiddle

Fractions
Let’s practice!
Get the white boards.
Parts of the fraction.
• What is the top number of a
2.
fraction called?
3
• The top number in a fraction is called
the numerator.
• What does the numerator tell you?
• The numerator tells you
how many parts or pieces you have.
1
2
• What is the bottom number of a
2.
fraction called?
3
• The bottom number in a fraction is
called the denominator.
• What does the denominator tell you?
• The denominator tells you
how many parts or pieces make one
whole.
1
2
3
Use your whiteboard
• How many pieces make one whole?
• How many pieces are blue? 3
• What fraction is shaded blue?
3.
4.
4
Use your whiteboard
What fraction is shaded blue?
2.
5.
Use your whiteboard
What fraction is shaded blue?
How about now?
2.
8.
1.
4.
Use your whiteboard
What fraction is shaded blue?
How about now?
How about now?
2.
6.
2.
6.
1.
3.
Use your whiteboard
What fraction is shaded blue?
How about now?
How about now?
2.
2.
8.
8.
1.
4.
Use your whiteboard
What fraction is shaded blue?
2.
5.
4.
10
6.
15
• What is 2/5 of 5?
• What is 2/5 of 10?
• What is 2/5 of 15?
2
4
6
Mixed Numbers
• What is a mixed number?
• A combination of a whole number plus a
fraction.
1 whole
¾
1¾
Mixed Numbers
• Any whole number can be written as a
fraction by putting the whole number in the
numerator and making the denominator 1.
• Examples:
• 3 = 3/1
5 = 5/1
56 = 56/1
Mixed Numbers
• We know that when we multiply the
numerator and denominator of a fraction
both by the same number it doesn’t
change the value.
• Examples:
• ½ x 3/3 = 3/6
• 2/3 x 4/4 = 8/12
Mixed numbers
• If you have a whole number, you can do
the same thing.
• 2/1 x 3/3 = 6/3
Mixed numbers
• If you have a mixed number like 21/3 try
this:
• 2/1 x 3/3 = 6/3
+
1/
3
7/
3
Mixed numbers
• When changing a mixed number into an
improper fraction, you want all the pieces
to be the same size. That is why you
multiply the whole number by the
denominator over itself.
• 34/5 = 3/1(5/5) + 4/5 = 15/5 + 4/5 = 19/5
Mixed Numbers
Write the mixed numbers as improper fractions:
• 3½
• 5 2/3
• 2 3/5
(3 x 2) + 1
2
(5 x 3) + 2
3
.
=
=
.
2