1. April 14, 2009 “Teach the children so that it will not be necessary to teach the adults.” ~Abraham Lincoln

2. April 14, 2009 Test 3  Thursday, 4/16 Covers: Text sections 4.1, 4.2, 4.3, 5.2, 5.3 Class Notes (fractions) Explorations 4.2, 5.8, 5.9, 5.10, 5.12, 5.13, 5.14, 5.15 *Class Notes (fractions) are due on 4/16*

3. April 14, 2009 Answers to HW 12 (section 5.2) are posted online Exploration 5.15 Review for Exam

4. Exploration 5.15 On page 119, do 1a and 1b individually. At your table, discuss #2. Individually try 3a – 3c for 3 minutes. Then, compare answers as a group. As a group – write 2 sentences that would help someone who has not done this exploration.

5. Review for Exam 3 We know that, to add or subtract fractions, a common denominator is needed. Why is this true? How is this process related to the LCM we discussed in Chapter 4?

6. Review for Exam 3 2/5 + 1/3 = 11/15. Write the three related facts. 3/8 × 4/5 = 3/10. Write the three related facts. What is wrong with this? If 3/8 × 48 = 18, then 48 ÷ 3/8 = 18; 3/8 ÷ 48 = 18; and 48 ÷ 18 = 3/8.

7. Review for Exam 3 Is this correct? 8 3/4 × 2 7/8 = (8 × 2) + (3/4 × 7/8) = 16 21/32 What happens if we get a common denominator before multiplying 3/4 × 7/8?

8. Review for Exam 3 Chapter 4 topics: Even/odd Prime/composite Prime factorization GCF/LCM Relatively prime: 2 numbers who share no factors except for 1. Examples: 27 and 28, 9 and 13, 16 and 25 Divisibility rules may be helpful

9. Review for Exam 3 Chapter 5 topics: Picture models for part of a whole: area, discrete, number line (measure) Word problem models for fraction: part of a whole, ratio, operator, quotient. A variety of different ways to compare fractions. Draw pictures – given a whole, find a fraction; given a fraction find another fraction of the same whole, etc.

10. Review for Exam 3 Some sample problems: 1. Given these 8 numbers: 3, 7, 10, 17, 27, 44, 71, 115 a) What fraction of these are odd? b) Write a ratio of prime numbers to composite numbers. 2. a) Find the GCF of 10 and 115. b) Find the LCM of 10 and 115.

11. Review for Exam 3 3. Show that 14/5 > 8/5 using the area, discrete, and number line picture models. 4. List as many ways as you can to show that 1/2 < 2/3: no LCD or decimals. 5. Write word problems for 4/6 using the operator and quotient models.

12. Review for Exam 3 6. If is 3/4, find 1 2/3. 7. If is 4/5, find 1/2.

13. Review for Exam 3 8. Compute: 1 3/4 + 7/8; 1 3/4 - 7/8; 1 3/4 7/8;1 3/4 ÷ 7/8. 9. a) A student says that 4 2/3 + 3 1/4 = 7 3/7. What would you say to this student? b) A student says that 3/4 ÷ 1/2 = 8/3 or 2 2/3. What would you say to this student?

14. Homework Class Notes (fractions) – due Thursday, 4/16 by 3:00 pm (I’ll be in my office from 2 – 3:00). Link to online homework list: http://math.arizona.edu/~varecka/302AhomeworkS09. htm *Note: approximate grades so far are posted on D2L Exam 3: Thursday, 4/16.