Chapter 4 Review: Part 2

October 22nd 2008

Ms. Dewey-Hoffman

Simplifying Fractions (4.4)

Equivalent fractions are fractions that look the same, but when simplified both give the same fraction in simplest form.

A fraction is in Simplest Form when the numerator and the denominator have no factors in common other than 1.

When simplifying fractions, write the factors. Cancel out the common factors on the top

and bottom.

Try These:

25n3a5/100n2a10 =

9h2b/18ha =

309t4s2/6t4s =

Reasoning Strategies (4.5)

Word Problems! Look for all of the possibilities. Make sure you have them all. If it helps: Make Diagrams If it helps: Shorten things. Example: Sammy, Jenny and Ben. Shorten

to S, J and B.

Baseball Games

There are seven baseball teams in a league. Each team plays each of the other teams twice. What is the total number of games played?

Team 7: 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1. 2x6 = 12 Games. Team 6: 5, 5, 4, 4, 3, 3, 2, 2, 1, 1. 2x5 = 10 Games Team 5: …Figure out the pattern. How many

Games? 42 Games Total.

4.6: Rational Numbers

Rational Number: any number that can be written as a fraction, decimal, or ratio

(hence RATIOnal Number) There are an unlimited number of equivalent

fractions for every rational number. Also, remember you can graph rational

numbers on a number line.

Rational Numbers and Variables

To evaluate fractions with variables: Remember that the fraction bar is a grouping

symbol! First: substitute for variables. Second: Simplify above and blow the line. Third: Write the fraction in simplest form.

Try These:

(x2 + y) + 5 / 25, for x = 10, y = 20

45 – t / t – 52, for t = 28

3 3 y / y + 36, for y = 9

4.7: Exponents and Multiplication

Multiplying two powers with the same base? Just add the exponents. 52 58 = 510

x4 x7 = x11

Taking the Power of a Power? Just multiply both exponents.   (34)3 = 312

(m9)2 = m18

Try These:

-7x6 -5x8

(d5)8

x_ x12 = x15

(r4)_ = r20

4.8: Exponents and Division

When dividing two powers with the same base: Subtract the exponents.

When dividing exponents and you come across a negative exponent…

Put the negative exponent below a fraction bar. Positive exponents above the fraction bar. Negative exponents go below the fraction bar. If you get rid of everything above or below the

fraction bar it is now 1.

Try These:

5x2 / 10x-5

67 / 611 

42a6b7 / 7a3b3

Write as a Fraction: 4t3y-4

Write without a Fraction: 21x6r5 / 7x7r2

4.9: Scientific Notation

Re-writing numbers, either extremely large or small, using powers of 10.

Negative powers of 10 are small numbers, less then 1 and greater than 0.

Positive powers of 10 are large numbers, much greater than 1.

Standard Scientific

Scientific Standard, a negative exponent says move the decimal to the left.

Scientific Standard, a positive exponent says move the decimal to the right.

Standard Scientific, really small number means negative exponent.

Standard Scientific, large number means positive exponent.

Order and Compare

Re-write in Scientific Notation Compare Exponents Compare Decimals Put in Order as Directed Re-write with Original Numbers

Multiplying in Scientific Notation

When multiplying Scientific Notation… BREAK INTO FACTORS!!!! Then MULTIPLY!

Try These:

8.43 x 106

2 x 10-4

(7 x 102)(17 x 1016)

0.0000000005067

3,405,000,000

Assignment #28

Pages: 217-218: 26-66 All. PLUS! Definitions to the bolded words in those three

sections: Equivalent Fractions, Simplest Form, Rational Number, and Scientific Notation. 

We’re going to do a game on Friday, sorry Folks.

Chapter 4 Test Tomorrow. Extra Credit is: Page 219: All. (1-76).