TEMPERATURE

The temperature of something tells us how hot

or cold something is.

TEMPERATURE IS MEASURED IN DEGREES USING A THERMOMETER

IS THE SYMBOL FOR DEGREES.

100 “100 Degrees”

A thermometer is an instrument that is used to

measure temperature.

How to Read a Thermometer

Temperature is measured on two scales: Celsius and Fahrenheit.

98.637 C F

Earlier in the century, Fahrenheit and Celsius used water as the basis of their thermometers.   Their thermometers were calibrated using water, which

everyone had access to.  This made their thermometers useful to everyone. In the same way, the meter could be useful to

everyone.

°F, the Fahrenheit Scale (used in the US), and°C, the Celsius Scale (part of the Metric System, used in most other countries)

They both measure the same thing (temperature!), but use different numbers:

Boiling water (at normal pressure) measures 100° in Celsius, but 212° in Fahrenheit

And as water freezes it measures 0° in Celsius, but 32° in Fahrenheit

CELSIUS AND FAHRENHEIT.

Celsius °C Fahrenheit °F

A measurement of temperature using a scale on which water boils at 100 degrees and freezes at 0 degrees. It is sometimes called centigrade.

A measurement of temperature using a scale on which water boils at 212 degrees and freezes at 32 degrees.

“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?

CONVERTING

Looking at the diagram, notice: The scales start at a different number

(0 vs 32), so we will need to add or subtract 32 The scales rise at a different rate (100 vs 180),

so we will also need to multiply

CONVERTING

FORMULA Celsius to Fahrenheit:   (°C × 9/5) + 32 = °F

Fahrenheit to Celsius:   (°F − 32) x 5/9 = °C

°C to °F

Multiply by 9, then divide by 5, then add 32

°F to °C

Deduct 32, then multiply by 5, then divide by 9

CONVERSION GUIDE

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

1. 5° C

2. 35° C3. 20° C4. 15° C