Catalyst January 7(5-

3),

2011 HW OUT! Check out

the‘graph’ to

theright.

Determine who the “Biggest Rapper Alive” is and back up with at least 2 reasons (must be from graph!).

Today’s Agenda

Catalyst Go over yesterday’s Exit Question/HW Sig Figs Intro to Dimensional Analysis Work Time Group of the Week and Exit Question

Book HW: Chapter 5 Review Questions

24, 26, 39, 40

Today’s Objectives

SWBAT determine the number of significant figures in a number.

SWBAT convert units like it’s hot…by using dimensional anlaysis.

Analyze1 of the 12 Testing Power Words! Example: Analyze the experimental data to formulate a conclusion. Analyze how the author uses personification. Break down Figure out Scrutinize Interpret

Exit Question

Describe the accuracy (A) and precision (P) of 1 & 2.

What prefix/unit would you

use to measure the

volume of cold drink in

a can?

What prefix/unit

would you use to measure

the length of your pinky?

Pop Quiz #2

1. How many significant figures are in the number 1457?

2. Round the following number to 2 significant figures: 1.33

3. About how many pounds are in 1 kilogram?

4. 1 dozen = 12 is an example of what two-word term?

Significant Figures

Key Point #1: Know the Sig Fig Rules starting on page 124!!! (esp. 1 & 2!!)

1. Nonzero integers always count as sig figs. Ex: 1457 has 4 sig figs

2. There are 3 class of zeroesa. Leading Zeroes (not sig figs) Ex: 0.0025b. Captive Zeroes (are sig figs) Ex: 1.008c. Trailing Zeroes (sometimes sig figs) Ex: 100 vs. 100.

Counting Sig Figs: Examples Give the number of sig figs for

each of the following measurements:

a. 0.045b. 3.402x102

c. 49.2d. 4500e. 290.

Rounding Off Numbers

Key Point #2: Know the Rounding Rules on page 126 (esp. 1!!)

1. If the digit to be removed…a. is less than 5, the preceding digit stays

the same Ex: 1.33 rounds to 1.3

b. is equal to or greater than 5, the preceding digit is increased by 1

Ex: 1.36 rounds to 1.4Ex: 3.15 rounds to 3.2

Ex: 4.57 rounds to 4.6

Rounding: Examples

Round the following numbers to 2 sig figs:a. 4.36b. 321c. 0.00563d. 2.09

Round the following numbers to 3 sig figs:a. 6389b. 4082c. 0.02751d. 2.198x10-3

CONVERSIONS

GET READY FOR AWESOME!

Convert it like it’s hot

Key Point #3: A conversion factor shows the same value with two different units. YOU ALREADY KNOW THIS STUFF! Examples:

10 dimes= 1 dollar 20 nickels= 1 dollar 4 quarters= 1 dollar

Dimensional Analysis

Key Point #4: Dimensional analysis is a tool used to convert from one unit to another.

Working on the Railroad

Step 1: What to what?

Step 2: Write conversion factor(s)

Step 3: Train tracks

Practice! One-step problems. How many meters are in 10 centimeters?

How many centimeters are in 327 meters?

Practice! On your own!

The distance from New Orleans to Miami is 1387 kilometers (862 miles). Convert 1387 kilometers to meters!

Exit Question

In July 2008, it was estimated that the world’s population is about 6,707,000,000. The United States’ population was estimated to be 304,060,000. The coldest temperature ever created by man is 0.000000005 Kelvin. Write the 3 bolded numbers in scientific notation and determine the number of sig figs for each.