Return to Mathematics IndexMath Technique in Multiplication and Division of Fractions

Garth, Frieda Farragut Career Academy

762-2421

Instructional Objectives:1. To multiply fractions by whole numbers and fractions. 2. To divide fractions by whole numbers and fractions.Review Objective:To review unit concepts and skills.Apparatus Needed:2-Poster Boards (size 22" x 28") divided in three parts: center square (8"x 8"); second section (9" x 7 1/2") from center point of the poster; third section (out side spaces) (5 x 3 1/2") from second section. Center square is used for placing different numbers as the whole number or mixed fractions. The second sections are used for fractions. The third sections (outside spaces) are used for one or two answers. Black marker, ruler, magnetic tape and nine (9) squares (8"x8") with numbers from 2, 3, etc. The fractions were placed in the second section with a black marker before laminating, which was done at the Bd. of Ed., 3th floor west.Recommended Strategy:This mini teach is directed toward learning disabled students, but this is a problem common to all students. To understand the basic concepts of fractions, demonstrate step-by-step procedures to be used in this lesson. Teacher will use center square of the posterboard, placing a whole number in the center. Fractions are on the second section of posterboard and the third section of the posterboard will be used to compute student answers. Example 8 x 3/4 = 6; 8 x 1/6 = 1 1/3. Posterboards will be attached to blackboard with magnetic tape. These steps (multiplication or division) may be repeated more than once, because there are eight fractions on each board and a different whole number can be used as often as needed. Students will note that their answers can be found simply by multiplying whole number by numerator, then divide by the denominator to get the product. Teacher will introduce concept of dividing fractions with second posterboard in the same method, step-by step procedures in dividing fractions. Give the numerators and denominators colors, like red for numerators and green for the denominators. Students can see the interchanging of numerator and denominator, which is called the reciprocal of the fraction. Example, the reciprocal of 3/4 is 4/3. Have the students complete the exercises, this can be used to provide stimulation and practice. This step may be repeated more than once, because there are eight fractions on each board and use a different whole number, if you so desire. Have the student to note that answers could be found simply by multiplying whole number by numerator, then dividing by the denominator to get the product.