Before the bell rings... Have your assignment out on your desk. Have your covered textbook with you.

1. Which type of graph would be the best choice to represent data that shows an increase (each year) over a ten-year period in the number of worms the champion bird can swallow?

A) Line graph B) circle graph C) double bar graphD) pictograph

2. A travel company brags that 94% of its trains are on time. The company runs 250 train trips a week. How many are on time?

Before the bell rings... Have your assignment out on your desk. Have your covered textbook with you.

1. Which type of graph would be the best choice to represent data that shows an increase (each year) over a ten-year period in the number of worms the champion bird can swallow?

A) Line graph B) circle graph C) double bar graphD) pictograph

2. A travel company brags that 94% of its trains are on time. The company runs 250 train trips a week. How many are on time?

235

Day Two of Subtracting Integers

Using Variable ExpressionsWord Problems /

Applications

EXAMPLE 2 Evaluating a Variable Expression

Evaluate 15 – a – b when a = 24 and b = – 36 .

15 – a – b = 15 – 24 – (–36)

= 15 + (–24) + 36

= –9 + 36

= 27

Add the opposite of 24 and of –36.

Add –9 and 36.

Substitute 24 for a and –36 for b.

Add 15 and –24.

GUIDED PRACTICE for Examples 1, 2, and 3

a – b – (–6) = 8 – (–15) – (-6)

= 8 + 15 + 6

= 29

Add the opposite of –15 andof –6.

Substitute 8 for a and –15 for b.

Add.

a – b – (–6) a = 8, b = –15

Daily Homework Quiz For use after Lesson 2.3

Evaluate the expression when z = 5 and w = – 6.

5) z – 13 – w 6) w + z – 14 + 30

Daily Homework Quiz For use after Lesson 2.3

Evaluate the expression when z = 5 and w = – 6.

5) z – 13 – w 6) w + z – 14 + 30

ANSWERS – 2 ANSWERS 15

Daily Homework Quiz For use after Lesson 2.3

7. Sam has a score of – 50 points in a game and then loses 20 more points.What is Sam’s final score?

Daily Homework Quiz For use after Lesson 2.3

7. Sam has a score of – 50 points in a game and then loses 20 more points.What is Sam’s final score?

ANSWERS – 70 points

GUIDED PRACTICE for Examples 1, 2, and 3

What is the difference in elevation between 4 feet above sea level and 30 feet below sea level?

The difference in elevation = 30 feet below sea level + 4 feet above sea level

= 34 ft

Distance

EXAMPLE 3 Standardized Test Practice

EXAMPLE 3 Standardized Test Practice

SOLUTION

The height is the difference of the upper and lower elevations.

Vertical height = –600 – (–1200) Write subtraction statement.

= –600 + 1200 Add the opposite of –1200.

= 600 Add

ANSWER The height of the SOFAR channel is 600 meters. The correct answer is C.

Homework- mental math 28) 35 – x = 45 29) -32 – x = -37

Assignment: P. 70 #19 -35, 43, 53, 55

Review for Quiz 2.1 – 2.3 Quiz tomorrow!! Know rules for

adding and subtracting integers.