Page 65 - Basic College Mathematics with Early Integers

42 C HAPTE R 1 I THE WHOLE NUMBERS

PRACTICE 6 Example 6 Estimating Distances

Tasha Kilbey is trying to esti-
A driver is trying to quickly estimate the distance from Temple, Texas, to
mate how far it is from Gove,
Brenham, Texas. Round each distance given on the map to the nearest ten to esti-
Kansas, to Hays, Kansas. Round
mate the total distance.
each given distance on the map
to the nearest ten to estimate
the total distance. Temple
79
36
Grainfield 16 miles 42 miles Cameron
Quinter 283
19 miles
11 miles Wakeeney 9 miles 190 190
40 183
Gove Milano
70
283 31 miles Texas
23 36
Hays 190
77 17 miles
Caldwell
21
290
33 miles
Kansas
290
Brenham
Solution:
Exact Distance: Estimate:
42 rounds to 40
9 rounds to 10
17 rounds to 20
33 rounds to 30
100
It is approximately 100 miles from Temple to Brenham. (The exact distance is
101 miles.)

Work Practice 6

PRACTICE 7 Example 7 Estimating Data
In a recent year, there were In three recent months, the numbers of tons of mail that went through Hartsfield-
48,445 reported cases of chicken Jackson Atlanta International Airport were 635, 687, and 567. Round each
pox, 6584 reported cases of number to the nearest hundred to estimate the tons of mail that passed through
mumps, and 15,632 reported this airport.
cases of pertussis (whooping
cough). Round each number to Solution:
the nearest thousand to estimate Exact Tons of Mail: Estimate:
the total number of cases
635 rounds to 600
reported for these preventable
687 rounds to 700
diseases. (Source: Centers for
567 rounds to 600
Disease Control and Prevention)
1900
The approximate tonnage of mail that moved through Atlanta’s airport over this
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period was 1900 tons. (The exact tonnage was 1889 tons.)
Work Practice 7

Answers
6. 80 mi 7. 71,000 total cases