TARGET AGE LEVEL: 5th Grade, one class period

INSTRUCTIONAL OBJECTIVES: Upon completion of the lesson, students will be able to add and subtract fractions with unlike denominators.

CONCEPTS/STANDARDS ADDRESSED: NCTM Standards 1-7, 12, 13

MATERIALS:
    Math Textbook: Mathematics Applications and Connections, (2001). Glencoe McGraw-Hill.
    Computer Lab

MOTIVATOR/ANTICIPATORY SET: Teacher will place 3 problems on the board as a quick review of previous lesson on adding and subtracting fractions with like denominators. Have three students come to the board and do the problems and explain their answers.

PROCEDURE/KEY DISCUSSION QUESTIONS:
    1. Have volunteer read the opening problem on page 240 in text. While the teacher draws the pie on the board divided into eighths and then another divided into sixths, students will work with the grid paper to draw their own illustration of eighths and sixths. Using colored pencils, color in the two fractions illustrated (1/8 and 3/6). Talk about the different illustrations and the common answers generated.
    2. Continue with examples on page 241, making special emphasis on the fact that the denominators are not the same.
    3. While doing sample problems, encourage students to estimate their answers first and then work the problem and compare their answers.
    4. To add fractions with unlike denominators, the least common denominator must be done first and the fractions converted accordingly.
    5. To subtract fractions with unlike denominators, the same steps must be followed.
    6. Continue working problems for additional practice, having students come to the board and then explain their answers.
    7. Particular emphasis must be paid to the sign used (addition or subtraction), as this is where students often become confused.

Day TWO: Computer Lab.
    1. Students will spend the class period in the computer lab.
    2. The website http://www.visualfractions.com/ will be used to provide students with additional practice at their own pace with working with adding and subtracting fractions.
    3. Students will be directed to work in the following categories: Renaming fractions, adding unlike denominators, and subtracting unlike denominators.
    4. For students that have a good grasp of the material, they may explore on their own, either using this particular site or finding another one and sharing it with the class.

CLOSURE: Review the rules for adding and subtracting fractions with unlike denominators. Emphasize that the website gives students a more visual way of seeing why the LCD is needed when adding and with unlike denominators.

ASSESSMENT: Students will be assessed by their participation in class, their cooperation, and their performance on Practice worksheet 7-3, selected problems. They will also be assessed on their knowledge of navigating the website and the ability to perform problems accordingly.