Key Concepts and Ideas For
Fill in the blanks for the following.
Then come up with an example that illustrates each. Hold the mouse
over the yellow box to check your answer.
top number of a fraction is called the
bottom number of a fraction is called the
prime numbers below twenty are 2, 3, 5,
reduce a fraction we can cancel out
change a mixed number to an improper fraction, multiply the
and add it to the
multiplying proper or improper fractions, first
multiplying a whole number by a fraction, first change the whole number
and then multiply
divide proper or improper fractions, change to a multiplication by
multiplying by the
multiplying or dividing mixed numbers, you must first change the mixed
before multiplying across.
find the least common denominator (LCD) of two or more fractions by finding
the least common multiple of the
find the least common multiple, first write each of the numbers as a product
and then use each
number of times it
appears in any denominator.
build two fractions, first find the
, and then find how
many times the
must be multiplied
to get the LCD. Finally
by this number.
add fractions with the same denominators, you get the sumís numerators
the two numerators,
while the sumís denominator is
add or subtract proper or improper fractions with different denominators,
first find the
up the fractions,
and finally add the two fractions.
add mixed numbers, separately add the
parts and the
If the sum of the fractional parts produces an improper fraction,
change the improper fraction to a
Then add the 1 to the whole number sum.
subtract mixed numbers, separately subtract the
parts and the
Then build the fractions. If
the first fraction is smaller than the second, then
1 from the whole
number. Write this 1 as
. Finally add and
subtract the fractions.
order of operations is
. If there is a tie,
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