Download Division of Fractions - Norwell Public Schools

April 10, 2014
Warm Up
Simplify the following. Show all work.
1
2.5 + 3 4
1
2
.
5
6
April 10, 2014
Dividing Fractions and Mixed Numbers
April 10, 2014
Lesson Objective:
Students will learn to divide fractions and mixed numbers by using the "keep, switch, flip" process (multiplying by the reciprocal) in order to solve real-world mathematical problems.
Key Terms: reciprocal, multiplicative inverse
April 10, 2014
Independent Activites:
1.) Khan Academy: "Dividing mixed numbers and fractions"
watch video & write down three things that you have learned, already knew, or have questions about. 2.) BrainPOP
watch video & take the quiz
3.) Practice - you may work with a partner to complete
4.) Classwork quiz - what did you learn?
April 10, 2014
reciprocal
To find the reciprocal of a fraction, simply exchange the top and
bottom of the fraction.
3
Example 1: The reciprocal of is 4
4
3
Example 2: The reciprocal of 2 is 1
2
April 10, 2014
multiplicative inverse
The product of a nonzero number and its reciprocal, or
multiplicative inverse, is 1.
Examples:
1.)
2.)
convert to an improper fraction
3
15
4
.
4
15
= 1
April 10, 2014
Independent Practice: Find the reciprocal
1.) 1
5
.
= 1
2.) 1
2
3
.
= 1
April 10, 2014
Using reciprocals to divide fractions and mixed numbers
1.) KEEP the first number the same
2.) SWITCH the division symbol to multiplication
3.) FLIP the second number to its reciprocal
3
1
4
2
Switch
Keep
3
4
.
2
1
Flip
After you KEEP, SWITCH, FLIP multiply the fractions.
April 10, 2014
Independent Practice: Divide, write each answer in simplest form.
1.) 4
5
5
2.) 2 1
2
1
3 6
April 10, 2014
Real-World Application.
Use RUCO to solve the following word problem. Show all work and label your answers.
1
At Lina's restaurant, one serving of chili is 1 cups. The 2
chef makes 48 cups of chili each night. How many servings of chili are in 48 cups?
April 10, 2014
Additional Practice: