1. Fill the boxes to make equivalent fractions . Show your
work.
2. There is a bag filled with 50 squares. Some of the
squares are red , the rest are yellow.
You reach into the bag and randomly pick out 10 squares. 3 of the 10 squares you
picked
are red. What is the best scientific guess about how many red squares are in the
bag?
Explain.
3. There are 100 light bulbs in a box at a factory. A factory worker tests 10 of
the light
bulbs to see if they work properly. 2 of the light bulbs of the 10 he tested do
not work
properly. What is the best scientific guess about how many light bulbs in the
box do not
work properly? Explain.
4. Fill the boxes to make equivalent fractions. Show your work.
5. There is a bag filled with 40 squares. Some of the
squares are yellow, the rest are green.
You reach into the bag and randomly pick out 10 squares. 6 of the 10 squares you
picked
are yellow. How many yel low squares are in the bag? Give your best scientific
estimate.
Explain your answer.
6. Fill the boxes to make equivalent fractions.
[The following hint was given to the students after they
attempted the problems. Students
were then allowed to work on the problems some more.] Remember that there are
two
ways to get equivalent fractions. We can either multiply the numerator and
denominator
by the same number or we can divide the numerator and denominator by the same
number.
7. There is a bag filled with 50 squares. Some of the squares are yellow, the
rest are green.
You reach into the bag and randomly pick out 10 squares. 3 of the 10 squares you
picked
are yellow.
(a) Give the best scientific estimate for the total number of yellow squares in
the bag of
50 squares:
Show your work.
(b) Does your best scientific estimate necessarily give you the exact correct
number of
yellow squares in the bag? Explain why or why not.
[The following hints were given to the students after they
attempted the problems. Stu-
dents were then allowed to work on the problems some more.]
(a) Since 3 out of 10 squares picked were yellow,
of the squares picked were yellow.
Our best scientific guess is that in the whole bag, an equivalent fraction of
the 50
squares should be yellow. What fraction with denominator 50 is equivalent to
?
(b) If we picked another 10 squares from the bag would we necessarily get 3
yellow
squares again?
