numerator of a fraction is larger than the denominator, such as 23/7—it is called an
improper fraction.
How are fractions converted to decimalsand vice-versa?
In the most commonly used place value, the decimal system, numbers smaller than 1
can be expressed as fractions called decimal fractions. In this system, the decimal frac-
tions are expressed in terms of tenths, hundredths, thousandths, and so on. For exam-
ple, for the fraction 1/2, or 1 divided by 2, the decimal fraction is 0.5; and, vice versa,
the decimal fraction 0.5, or 5/10ths, is equal to 1/2.
Not all fractions are so easily converted to decimals. It depends on the type of
number, especially if it is an irrational or rational number. Some decimal fractions
include an infinite number of decimal places to be expressed exactly; something that
is not possible as far as we know (who can write an infinite number of numbers?) And
some decimal fractions repeat forever, such as 1/3 0.3333....
What are the rulesfor adding and subtracting fractions?
When adding fractions, the denominators need to be the same, but you can’t add the
denominators to get the answer. Simply put, if the denominators are already the same,
the fractions are simple to add, such as 1/3 1/3 (1 1)/3 2/3. If the denomina-
tors are not the same, find the common denominator by multiplication. For example,
1/2 1/3 3/6 2/6 (3 2)/6 5/6.
When subtracting fractions, the denominators again need to be the same; and
again you can’t add (or subtract) the denominators to get the answer. If the denomina-
tors are the same, subtract the fractions, such as 2/3 1/3 (2 1)/3 1/3. If the
denominators are not the same, find the common denominator by multiplication,
such as 1/2 1/3 3/6 2/6 (3 2)/6 1/6.
What are the rulesfor multiplying and dividing fractions?
As to be expected, there are rules for multiplying and dividing fractions. Multiplication
of fractions is very straightforward—just multiply the numerators and denominators, 99
MATH BASICS
Can a fraction’s numerator be zero?
I
n the context of division (see above), we learned that it is not possible to divide
by 0, which is labeled an undefined number. But you can have zero (0) as your
numerator. And any allowed fraction (one that doesn’t have a 0 in the denomina-
tor) that has 0 as its numerator will always be equal to zero. For example, 0/5
and 0/345 both equal 0.