Subject: Math / Grade Level(s): 6-7
Teacher: / Time Frame: 60 minutes
Lesson Summary:
Students will be able to multiply and divide fractions and decimals.
Lesson Objectives
The students will know…· How to identify the reciprocal of a number.
· That dividing by a fraction is the same as multiplying by its reciprocal.
· How to multiply fractions, including mixed numbers.
· How to divide fractions, including mixed numbers.
· How to multiply decimals to hundredths.
· How to divide decimals to hundredths.
The students will be able to…
· Multiply and divide fractions and decimals.
Lesson Plan
Time: / Procedure: / Materials Needed:
5 minutes / Warm-up Exercise:
Show slide 2. Review mixed numbers and improper fractions and how to change a mixed number to an improper fraction. Introduce the term reciprocal and show students how to find the reciprocal of a number. Then point out the matching mixed numbers and improper fractions and the numbers and their reciprocals on the slide. Ask students what they notice about the reciprocals. / PowerPoint Presentation, slide 2
10 minutes / Motivation (Real-world Applications):
Tell students that a lumberyard wants to cut a 4.5-foot piece of timber into smaller pieces that are each 0.5 feet long. Ask: After the timber is cut, how many pieces will there be? Have students write the problem using decimals and then write it using fractions. Help students find that there will be 9 pieces of timber. Students may want to use models to solve the problem. After the activity, tell students they will learn how to divide fractions and decimals to solve problems like these.
Have students give examples of other real-world situations in which they might divide or multiply fractions or decimals to solve a problem.
20 minutes / Presentation of New Material:
When presenting slides 3–8 on multiplying and dividing fractions, emphasize that checking for common factors before multiplying will make computations easier. When presenting slides 9–12 on multiplying and dividing decimals, make sure students understand how to place the decimal point in the product and quotient. When dividing by a decimal, help students to choose a power of 10 that will make the divisor a whole number. Caution students to multiply both the divisor and dividend by the same power of ten. / PowerPoint Presentation, slides 3–12
10 minutes / Guided Practice:
Have students work in pairs. Each student in the pair draws a number from the fraction box and the decimal box. Together, the pair multiplies and divides the two fractions (or mixed numbers) and the two decimals. / Fraction Box and Decimal Box (separate boxes with slips of paper on which is written one fraction or mixed number or one decimal in tenths or hundredths)
10 minutes / Independent Practice:
Have students choose two fractions or two decimals to multiply and/or divide. Then have students write and illustrate a "how-to" guide that explains how to multiply or divide the fraction or decimal. / Fraction and Decimal Boxes from Guided Practice; colored pencils; several sheets of plain paper per student
5 minutes / Closing Activities:
Circulate among students and collect one how-to guide from each student to share with the class or post in the classroom.
Homework: Have students complete the Study Island Worksheet on Compute Solutions.
Differentiation: Students needing additional support can use models such as fraction strips, tiles, grids, and pictures as necessary to help understand the concepts of multiplying and dividing fractions and decimals. They can also use models to verify that they have correctly multiplied and divided the fractions and decimals. Have students needing an additional challenge make up and solve word problems that require students to multiply or divide fractions or decimals.
Teacher Reflection:
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