How to Read a Thermometer

A thermometer is an instrument that is used to

measure temperature.

The temperature of something tells us how hot

or cold something is.

Temperature is measured in

degrees.

is the symbol for degrees.

100 “100 Degrees”

Temperature is measured on two scales: Celsius and Fahrenheit.

98.637 C F

“C” is the symbol for the Celsius scale.

C

The Fahrenheit scale is the most popular in the United States.

Its symbol is “F.”

F

Let’s count by 2’s…

2, 4, 6, 8, 10, 12…

The lines on most

thermometers count by two’s. 90

92949698

100102

F

8890929496

100

FWhat is the temperature

on this thermometer?

98 F

“98 degrees Fahrenheit”

7678808284

88

F90

Try this one.

86 F

“86 degrees Fahrenheit”

Normal body temperature is 98.6 F.

This means it is between 98 and 99 degrees.

98.6 F

This is a decimal point.

97 98 99

.2 .4 .6

98.6 F

The temperature is “98 point 6” degrees Fahrenheit.

96

98 99 100

.2 .4 .6 .8

99.8 F

The temperature is “99 point 8” degrees Fahrenheit.

97

100 101 102

What is the temperature?

101.2 F

99

Try this one.

102.8 F

101 102 103100

Negative Numbers

The temperaturescale is often seen

vertically.

As the temperature goes below freezing

we use negative numbers.

0

1

2

3

4

5

6

- 1

- 2

- 3

- 4

- 5

- 6

Water freezing

Getting warmer

Getting colder

SCALES

In U.S the Fahrenehit scale is used. The Celsius scale is used in almost all other

countries and by scientists.

Fahrenheit (1686-1736) established three fixed points on his thermometer.

0 degrees: temperature of an ice, water, and salt mixture.

32 degrees: water-ice combination stabilized at "the thirty-second degree."

98 degrees: “when the thermometer is held in the mouth or under the armpit of a living man in good health."

Celsius (1701-1744) established two fixed points on his thermometer.

0°C: representing the freezing point of water.

100°C: the boiling point of water.

PROBLEM

Riki measured the outside temperature at noon and then again at 8 p.m. The temperature at noon was 6°C. The temperature at 8 p.m. was – 2°C. What was the change in temperature?

1.You can use the thermometer like a number line.

There was a _____change in temperature.

PROBLEM SOLVING

One day the lowest temperature recorded in Maine was -12°F. The highest temperature in Maine that day was 25°F. What was the change in temperature?

Fórmula

°C  x  9/5 + 32 = °F

1)  Convert 37°C to Fahrenheit.37°C x  9/5 + 32 = 98.6°F

(°F  -  32)  x  5/9 = °C

2)  Convert 98.6°F to Celsius.(98.6°F  -  32)  x  5/9 = 37°C

•Use the formula to change each temperature to degrees Fahrenheit.

1. 5° C

2. 35° C3. 20° C4. 15° C