Weather Station: Readings and Departures

Distinguish greater readings from greater distances from zero.

Temperature and Distance from Zero

Use the temperature log for Questions 1–5. Absolute value measures distance from zero; it does not tell whether a temperature is warmer or colder.

Weather Station Temperature Log
Time	Temperature (°C)
5 a.m.	−9
8 a.m.	−4
Noon	6
3 p.m.	9

Which comparison shows that 8 a.m. was warmer than 5 a.m.?

A. |−4| > |−9|B. −4 > −9C. −4 < −9D. |−4| = |−9|

Compare the 5 a.m. and noon temperatures by their distances from 0°C.

The greater distance is °C. The temperature with that distance is °C.

How do the 5 a.m. and 3 p.m. readings compare?

A. The readings are equal, and their absolute values are equal.B. The 5 a.m. reading is greater, but its absolute value is smaller.C. The 5 a.m. reading is smaller, and its absolute value is smaller.D. The 5 a.m. reading is smaller, but their absolute values are equal.

Select every true statement about the temperature log.

Each statement is true. Sort it by what it compares.

Rainfall Departures

A rainfall departure is the amount above or below the usual rainfall. A negative departure means less rain than usual, not negative rainfall. Use the table for Questions 6–10.

Weekly Rainfall Compared with Usual
Week	Departure (mm)
A	−14
B	−6
C	10
D	0

Which statement correctly compares Weeks A and B?

A. Week A has a smaller signed departure but a larger rainfall shortage.B. Week A has a larger signed departure and a larger rainfall shortage.C. Week A has a smaller signed departure and a smaller rainfall shortage.D. Week A has a larger signed departure but a smaller rainfall shortage.

Compare Weeks A and C. Which signed departure is farther from the usual rainfall?

The departure farther from usual is mm. Its absolute value is mm.

Which pair correctly gives the greatest signed departure and the smallest absolute departure, in that order?

A. Week A; Week DB. Week C; Week BC. Week C; Week DD. Week A; Week B

A report says, “Week A had the greatest signed departure because 14 is the greatest absolute value.” Which correction is accurate?

A. Week D had the greatest signed departure; Week A was farthest from usual.B. Week C had the greatest signed departure; Week A was farthest from usual.C. Week A had the greatest signed departure; Week C was farthest from usual.D. Week C had the greatest signed departure; Week D was farthest from usual.

10.

The station flags a week when its rainfall departure is more than 8 mm from zero, whether above or below usual. Select all weeks that should be flagged.

Check New Station Reports

Decide whether each situation calls for comparing signed values or their absolute values.

11.

Two sensors record −2.5°C and 1.5°C. The station checks the sensor farther from 0°C first. Which reading comes first, and how does it compare numerically with the other reading?

A. The 1.5°C reading comes first; it is numerically smaller.B. The 1.5°C reading comes first; it is numerically greater.C. The −2.5°C reading comes first; it is numerically greater.D. The −2.5°C reading comes first; it is numerically smaller.

12.

Two new weeks have rainfall departures of −7.5 mm and −3.5 mm. A summary must name both the greater signed departure and the greater shortage.

The greater signed departure is mm. The greater shortage has a size of mm.

13.

A station's rainfall departures are −11 mm in one week and 11 mm in another. Which sentence belongs in its report?

A. The departures are equal, but the first departure is farther from zero.B. The first departure is greater, but both departures are equally far from zero.C. The second departure is greater, but both departures are equally far from zero.D. The second departure is greater, and it is also farther from zero.

14.

One morning the station reads −8°C, and that afternoon it reads 5°C. Write a short report with one inequality comparing the temperatures and one comparing their distances from 0°C. Explain what each comparison tells a reader.