1. Warm-Up Compare your answers for H13 with your colleagues (p. 303-305 # 3d, 30)

3. Announcements Exam on Friday, only 4 function calculators allowed (we have about 14- 15 in the classroom) Class notes due on Friday Office Hour today at 11am-12pm in MATH 303

4. What you need to know… Ch. 4 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

5. Some Problems Given these 8 numbers: 3, 7, 10, 17, 27, 44, 71, 115 What fraction of these are odd? Write a ratio of prime numbers to composite numbers. Find the GCF of 10 and 115. Find the LCM of 10 and 115.

6. What you need to know… Ch. 5 Picture models for part of a whole: area, discrete, number line (measure) Word problem models for fraction: part of a whole, ratio, operator, quotient. At least 5 different ways to compare fractions. Draw pictures--given a whole, find a fraction; given a fraction find another fraction of the same whole.

7. Some Problems Show that 14/5 > 8/5 using the area, discrete, and number line picture models. List as many ways as you can to show that 1/2 < 2/3: no LCD or decimals or one that requires visual verification. Why can you use the area model/number line in the problem above? Write word problems for 4/6 using the operator and quotient models.

8. Some Problems If is 3/4, find 1 2/3. If is 4/5, find 1/2.

9. What you need to know… Ch. 5 How to do all the operations on fractions (division after exam).

10. Multiply Fractions Multiply using the standard algorithm: Write as fractions (improper is okay), and then multiply numerators and denominators. 3/8 4/12 = (3 4)/(8 12) = 12/96 = 1/8

11. Add Fractions Add using the standard algorithm: Write as fractions (improper is okay), and then multiply each fraction by (a fraction equivalent to) 1 so that you obtain equivalent fractions with a (least) common denominator. 3/8 + 4/12 = (3/8) (3/3) + (4/12) (2/2) = 9/24 + 8/24 = 17/24

12. Sample Problems Compute: 1 3/4 + 7/8 1 3/4 - 7/8 1 3/4 7/8