To begin the lesson, you may wish to read a book about food [several are suggested in the Bibliography of Books About Food] and review the sections of the food pyramid. Ask the students to select foods from any two sections of the food pyramid so that seven foods will be selected in all. Record the
students' choices on the board or overhead projector. You might copy the colored pictures of the foods to transparency film for use on the overhead projector.
Then ask volunteers to name how many foods came from each section of the food pyramid. Write the corresponding number sentence where all the students can see it. Now ask them to select seven foods in another way. Remind the students that they may use more than two addends if they wish.
Call on several students to tell their choices, and record each in a number sentence on the board. Repeat the activity with other numbers up to 12. To record the ways a number can be decomposed into addends, ask the students to
draw a meal on their paper plate so that they will have five items in the meal. Encourage them to record the modeled addition sentence on the back of the paper
plate. Then call on volunteers to tell how they created a meal of five items. You may wish to display these drawings or place them in the students' portfolios.
Ask the students to focus on the vegetable section of the pyramid. Ask how many servings are required each day [three to five]. Now ask the students to draw on a 10 strip that has been cut in half.
Draw or paste two to four pictures of vegetables, one in each section of the strip. Model how
to write a missing addend statement that describes how many vegetables must be drawn to complete the "5" strip. [For example, if three vegetables have been drawn, the sentence would be 3 + _ = 5.] Place the students in pairs, and have
them compare the number of food pictures they drew with the number sentences.
Ask the students to exchange papers, complete their partner's strip, and fill in the missing addend. Call on volunteers to describe the strip using words and then using a subtraction sentence. Repeat the procedure, using the other half of the 10 strip and allowing the students to select up to five foods from either the fruit or vegetable sections. When the students are ready, call them together. Display the strips that they drew and the related number sentences with missing addends. If no students choose a number sentence in which the missing addend is zero, model this for the students.
For the second half of the lesson, divide the class into groups, and tell the students that they are going to act out stories about making healthy food choices. Assign one group of students to each section of the food pyramid, and ask them to draw one food from that
section on their paper plate. In turn, call on one volunteer from each group to select a day's worth of healthy foods from among the student drawings. For each
section, assign a volunteer to record the number sentences that the groups are modeling. [For the group assigned to the fruit section, for example, if two students drew oranges, one student drew an apple, and another drew a pear, the number sentence would be 2 + 1 + 1 = 4.]
Call out the food groups one at a time and ask the students who drew the pictures in that group to stand. Record the group and the number of students on the board [fruits, six; vegetables, eight]. Now ask a student to name any food group, note how many students are in that group, and write a missing addend statement on the board [6 + __ = 8]. Next, have the student call on the number of students to come to the front of the room that are required to represent the given addend [6].
Ask the other students, "How many more students need to join them to make the addition sentence correct?" [Two] Have the volunteer give the answer by calling the correct number of additional students to the front and completing the number sentence. [For example, if the sentence is 5 + _ = 9, five students will be called in the first group and then four more called.] Then, call on other volunteers to provide and model other number sentences with missing addends.
