1. EXAMPLE 2 Using Integer Subtraction Geography The highest point in Asia is Mount Everest at 8850 meters. The shore of the Dead Sea, the lowest point in Asia, is about 410 meters below sea level. What is the difference between these elevations? SOLUTION STEP 1 Represent the two elevations with integers. Mount Everest: 8850 mDead Sea: –410 m

2. EXAMPLE 2 STEP 2 Find the difference of 8850 and –410 meters. 8850 – (–410) Rule for subtracting integers = 9260 Answer The difference between the elevations is 9260 meters. Add. = 8850 + 410 Using Integer Subtraction

3. EXAMPLE 3 Finding a Change in Temperature Weather In Fairfield, Montana, on December 24, 1924, the air temperature dropped a record amount. At noon, the temperature was 63 o F. Twelve hours later, the temperature was –21 o F. What was the change in temperature? SOLUTION Change in temperature = end temperature – start temperature = –21 – 63 Substitute values.

4. EXAMPLE 3 = –21 + (–63) Rule for subtracting integers = –84 Add. ANSWER The change in temperature was –84 o F, so the temperature dropped 84 o F. Finding a Change in Temperature

5. GUIDED PRACTICE for Examples 2 and 3 ANSWER 543 ft ANSWER 44 o F Elevation Find the difference between an elevation of 535 feet above sea level and an elevation of 8 feet below sea level. 5. Temperature The temperature at 6 A.M. was – 12 o F. At 3 P.M. the temperature was 32 o F. What was the change in temperature? 6.