Video Transcript
The table shows the wingspans of
different birds. Name the bird that has the smallest
minimum wingspan and the bird that has the greatest maximum wingspan, and give their
wingspans in decimal form.
In the table, we are given three
birds together with their minimum and maximum wingspan. We are asked to find the smallest
minimum wingspan from the second column and the greatest maximum wingspan from the
third column.
Let’s begin by finding the smallest
value in the minimum wingspan column. Since seven is greater than six, we
can immediately rule out the whooping crane, which has a minimum wingspan of seven
and one-sixth feet.
As such, we need to compare the
minimum wingspan of the bald eagle and the black-footed albatross by considering the
fractions seven twelfths and three-tenths. We know that three-tenths can be
written in decimal form as 0.3, since three divided by 10 equals 0.3.
To convert seven twelfths to a
decimal, we can either use the fraction button on our calculator or we can divide
seven by 12. Typing this into our calculator and
using the SD button to convert from standard form to decimal form, we get an answer
of 0.58333 and so on. Since the digit three is repeating,
this can be written as 0.583 recurring as shown. We place a dot or bar above the
digit that is repeating.
We are now in a position to compare
the two decimal values. 0.3 is less than 0.583 recurring,
which means that six and three-tenths is less than six and seven twelfths. We can therefore conclude that the
bird with the smallest minimum wingspan is the black-footed albatross with a
wingspan of 6.3 feet.
Let’s now consider which bird has
the greatest maximum wingspan. All three birds have a maximum
wingspan equal to seven and some fraction, so we need to compare the three
fractions. The three fractions one-quarter,
one-half, and one twelfth are all unit fractions as their numerators are equal to
one. As such, we simply need to compare
their denominators. When positive fractions have the
same numerator, the fraction with the smaller denominator will be the greater
fraction. This means that one-half is greater
than one-quarter, which is greater than one twelfth, which in turn means that the
largest of the three mixed numbers is seven and one-half. We know that one-half is equal to
0.5. We can therefore conclude that the
bird with the greatest maximum wingspan is the bald eagle with a wingspan of 7.5
feet.
The two answers to this question
are black-footed albatross, 6.3 feet, and bald eagle, 7.5 feet.
