In module A, all the numbers that we encountered were whole numbers.
Although the whole numbers are important, they only tell part of the
story. Module B is the study of fractions
which are defined as parts of the whole.
Consider the picture below which might represent what is left of a
pizza. We see that the pizza was originally cut into eight slices and
there are three slices left. We say that there is
of the pizza remaining. The number 3 is
called the numerator
of the fraction and the number 8 is called the denominator
of the fraction.
Write the fraction of red circles in the diagram below.
We see that there are 9 total circles, 5 of
which are red. The total number of circles is the denominator and the
number of reds is the numerator:
Use a fraction to represent the shaded part of the
Hold the mouse over the yellow rectangle
for the solution:
Draw a sketch to illustrate 4/5.
Some Properties of
Recall that there were several properties of division. Since
fractions are really division problems, we arrive at the same properties:
If the numerator and denominator
are the same then the fraction equals 1:
If the denominator is 1 then the
fraction is just the numerator
If the numerator is 0 and the
denominator is not 0, then the fraction equals 0
If the denominator is zero then
the fraction is undefined
Application of fractions are encountered everywhere.
Example Use a fraction to describe each situation
Out of ten problems on the test you scored nine correct
You got 9/10 of the problems right
Of the 75 patrons on
Ellie's run, 61 were boarders
The fraction of boarders on Ellie's run was 61/75
Of the 51 bicycles at your rental shop, you discovered
that 8 needed repair.
8/51 of the bicycles needed repair.
Exercises Use a fraction to describe each
Of the seven students left in the class, three are
Seven days of January were snowy.
Fifteen of the ninety-one tourists are from Sacramento.
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