Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Bellringer
1) A ratio is a comparison of two quantites by ___________?
2) Write each ratio in simplest form:
a)
21
7
b)
4
36
c)
2 ft
30 in
d)
30 mL
2 L
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Check Your Homework
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Unit 3
Chapter 4 Section 2
Unit Rates and Proportional Reasoning
Objective: To find unit rates and unit costs using proportional reasoning
Rate: a ratio that compares two quantities measured in different units
Example: 15 grams of fat in 3 servings
15 grams fat
3 servings
Unit Rate: a rate for one unit of a given quantity
Example: 15 grams of fat in 3 servings (reduce)
5 grams fat
1 servings
Unit Cost: a unit rate that gives the cost per unit
Example: $3.50 for 5 apples (reduce)
unit cost = total price
size
$0.70
1 apple
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Examples:
Finding a Unit Rate Using Whole Numbers:
1) A package of cheddar cheese contains 15 servings and has a total of 147 grams of fat. Find the unit rate of grams of fat per serving.
2) Find the unit rate for 210 heartbeats in 3 minutes.
3) Find the unit cost for $42 for 4 shirts.
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Finding a Unit Rate Using Decimals and Fractions:
6
1
4) Cindy walks mile in hour. What is 10
4
her speed in miles per hour?
3
3
5) Find the unit rate for mile in hour. 10
4
6) Find the unit cost for $3.45 for 3.7 oz.
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Using Unit Cost to Compare:
7) Two sizes of shampoo bottles are shown. Which size is the better buy? Round to the nearest tenth.
16 oz
$6.19
13.5 oz
$3.99
8) Which bottle of apple juice is the better buy: 48 fl oz for $3.05 or 64 fl oz for $3.59?
9) Find the better buy: 8 pens for $3.60 or 12 pens for $4.80
Unit 3 Chapter 4 Section 2 Unit Rates and Proportional Reasoning.notebook
December 04, 2014
Homework:
Practice 4.2 #'s 1­12