How to Read a Thermometer

A thermometer is an instrument that is used to

measure temperature.

The temperature tells us how hot or cold something

is.

Temperature is measured in degrees.

is the symbol for degrees.

100 “100 Degrees”

Temperature is measured using two scales: Celsius and Fahrenheit.

212100 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

The lines on most thermometers are marked every 10

degrees.

60

F

70

80

90

60

70

80

90

The lines inbetween are usually counted by twos. However, you will always want to check to see if this is true for the thermometer you are reading.

60

F

70

80

90

Here is how we check:

Choose one of the marked lines and begin counting by twos until you get to the next marked line. If the number you say matches the number on the marked line then you know the lines on the thermometer are counted by twos.

7274

807876

70

Let’s try to read the temperature on this thermometer. We have already

checked to make sure the thermometer lines are counted by

twos.

60

F

70

80

90

The red liquid is past the 80 degree line but has not reached

the 90 degree line.

We start counting at the 80 degree line and we

count by twos.

The temperature on this thermometer is 82 F.

8082

Let’s try another one. We have already checked to make sure the

thermometer lines are counted by twos.

20

F

30

40

50

The red liquid is past the 40 degree line but has not reached

the 50 degree line.

We start counting at the 40 degree line and we

count by twos.

The temperature on this thermometer is 48 F.

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Let’s try one more. We have already checked to make sure the

thermometer lines are counted by twos.

10

F

20

30

40

The red liquid is past the 10 degree line but has not reached

the 20 degree line.

We start counting at the 10 degree line and we

count by twos.

The temperature on this thermometer is 16 F.

10

16

1214

So what do we do if we discover the lines are not counted by twos?

10

F

15

20

25

We must figure out what the lines are counted by…

Hint: Try counting by ones and then fives.

101112

Remember to start at one of the marked lines and count to the

next marked line.

The lines on this thermometer are counted by ones.

131415

Let’s try to read the temperature on this thermometer. We have already

checked and have found the lines are counted by ones.

10

F

15

20

25

The red liquid is past the 20 degree line but has not reached

the 25 degree line.

202122

We start counting at the 20 degree line and we count by

ones. The temperature on this

thermometer is 22 F.

Now let’s see if you can read some thermometers on your

own.

GOOD LUCK!