26 Chapter 1 Whole Numbers Example: Shawn has $52 and then spends $40. How much money does he have left? (In this problem, we subtract $40 from $52.) $52 $40 $12 2. The second type is phrased as an addition problem with a missing addend. Example: Maria received 72 points on her last math test, but needed 90 points to receive an A. How many more points would she have needed to earn an A? (In this problem, the addition problem can be translated to subtraction.) 72 ? 90 90 72 ? is equivalent to 90 72 18, Because Maria would have needed 18 more points. Solving an Application Problem Example 6 A biology class started with 35 students. By midsemester, 7 students had dropped. How many students are still in the class? Solution: There are 28 students still in the class. Solving an Application Problem 35 7 28 Example 7 A surveyor knows that the perimeter of the lot shown is 620 ft. Find the missing length. See Figure 1-5. Solution: Recall that the perimeter of a polygon is the sum of the lengths of its sides. The sum of the three known side lengths in Figure 1-5 is 480 ft: 1 100 175 205 480 175 ft 100 ft ? We can subtract 480 ft from the perimeter to find the missing length: The missing length is 140 ft. 620 ft 480 ft ? 6 5 12 0 2 4 8 0 1 4 0 205 ft A third application of subtraction is to compute a change (increase or decrease) in an amount. Answers 11. 13°F 12. 88 points Figure 1-5 Skill Practice 11. The temperature at 1:00 P.M. in Denver was 47°F. Three hours later, the temperature was 34°F. By how much did the temperature drop? Skill Practice 12. Teresa earned test scores of 98, 84, and 90 on her first three exams. How many points must she score on the fourth exam to earn a total of 360 points?
miller_basic_college_math_3e_ch1_3
To see the actual publication please follow the link above