Procedure

For the teacher:

*  Have students do the Pretest to asses students’ mastery of concepts and skills learned on
    comparing fractions and decimals, rounding numbers, adding, subtracting, multiplying,
    and dividing decimals and fractions, and relating fractions, decimals, and percents.

*  Provide students with experiences in shading 10 x 10 grids to represent given percents.
   ( This focuses on the basic concept of percent, that of “Parts per hundred).

  Example:

                                   

            Ask:  1.  How many small squares are in the model?
                      2. How many squares are shaded?
                      3. What fraction is represented by the shaded parts?
                      4. What decimal is represented by the shaded parts?
                      5. If the model represents 9%, what is your conjecture about the meaning of the word percent?

*  Provide some more exercises on expressing percents as fractions and decimals using the
   10 x 10 grid.

*  Using a 10 x 10 transparency,
         Ask:  1.  How many squares are in the grid?
                        Elicit that the 100 squares represent the whole.
                  2.  Shade 25 squares. Elicit that 25 of the whole is shaded.
                  3.  25% of 100 = 25.  How do you write this equation using a decimal and a
                       fraction?
                        Elicit that 25% of 100 = 25 can also be written as 25/100 x 100 = 25 and
                        0.25 x 100 = 25.  Point out that since 25/100 = 1/4, 25% of 100 is also
                        1/4 of 100.

*  Distribute grid paper to pairs of students.  Have them outline an 8 x 10 grid and 6 x 10
    grid with crayons or markers.  Elicit that there are 80 squares and 60 squares,
    respectively, in the outlined grids, and that each outlined grid represents a whole.
25%

 

     Ask:  1.  Shade 25% of the grid.
              2.  How many squares are in the grid?
                   Elicit that there are 80 squares.
              3.  What is 25% of 80?
                   Elicit from the students that 25% of 80 is 20.
              4.  How do you write this equation using a decimal and a fraction?
                   Elicit that 25% of 80 can be written as in two ways:  .25 x 80 or 1/4 x 80 = 20

*  Provide more exercises on finding percents of numbers.

*  Lead students to the activity for the day.
    Provide them with the following materials:  fish tank, fish and electronic scale

*  Discuss with the students the procedure for determining the weight of fish.
         1.  Find the weight of the container and water.
         2.  With the fish net, place the fish into the container with water and find the
               weight.
         3.  Subtract the weight of the container with water from the weight of the
              container, water, and fish.
         4.  The difference is the weight of the fish.
         5.  Repeat these steps for the other fish.
         6.  Use the feeding guideline: 6% of the fish body weight to determine the percent
                    of food to feed.
         7.  Make a table to record data collected.

      *  Have students work in small groups to perform the activity.

 

For the students:

     *  Use prior knowledge to answer the Pretest.
     *  Visualize the meaning of  finding the percent of a number through 10 x 10 grids.
     *  solve exercises on expressing percents as fractions and decimals.
     *  Work collaboratively in small groups to find the percent of a number.
     *  Work collaboratively in small groups to record container and water weight, fish
         weight, and percent of food to feed the fish.
     *  Make a table to record data collected through excel.
     *  Answer the post test to evaluate mastery of finding percents of numbers.

5.  Resources:
     *  Overhead projector/ transparencies
     *  Fish Tank with Tilapia Fish
     * Electronic scale

6.  Instructional/Environmental Modification
     *  Pretest; Post Test
     *  Cooperative groupings of students
     *  Use of calculators to find percents of number
     *  Create web links list for students to use to explore percents.

http://nlvm.usu.edu/en/nav/frames_asid_160_g_3_t_1.html?open=activities http://www.mathgoodies.com/lessons/vol4/meaning_percent.html http://www.math.com/school/subject1/lessons/S1U1L7GL.html#sm2 http://www.aaaknow.com/pct61ax2.htm#section2

 

For the students:

            *  Use prior knowledge to answer the Cycle Review.
            *  Visualize the meaning of percent through the 10 x 10 grids.
            *  Put students on the Web:               

http://nlvm.usu.edu/en/nav/frames_asid_160_g_3_t_1.html?open=activities http://www.mathgoodies.com/lessons/vol4/meaning_percent.html http://www.math.com/school/subject1/lessons/S1U1L7GL.html#sm2 http://www.aaaknow.com/pct61ax2.htm#section2