A thermometer is a tool that tells us how hot or cold something is. We can use a thermometer to check the air outside, a room, water, or a person’s body. Learning to read a thermometer helps us choose what to wear and understand the weather.
The red line shows the temperature.
Key Facts
- A thermometer measures temperature.
- Temperature tells how hot or cold something is.
- °F means degrees Fahrenheit.
- °C means degrees Celsius.
- Look at the top of the red line to read the temperature.
- A higher red line means warmer, and a lower red line means cooler.
Vocabulary
- Thermometer
- A thermometer is a tool that measures how hot or cold something is.
- Temperature
- Temperature is a number that tells how hot or cold something is.
- Degrees
- Degrees are the units used to measure temperature.
- Fahrenheit
- Fahrenheit is a temperature scale often used for weather in the United States.
- Reading line
- The reading line points to the number that matches the top of the red liquid.
Common Mistakes to Avoid
- Reading the bottom of the red liquid, not the top. The temperature is shown by the top of the red line.
- Skipping numbers between marks. Count by the pattern on the thermometer, such as 10, 20, 30, or by 2s or 5s.
- Thinking higher numbers mean colder. Higher numbers mean warmer, and lower numbers mean cooler.
- Forgetting the unit, like °F or °C. The number needs its unit so we know which temperature scale is being used.
Practice Questions
- 1 A thermometer has the red line at 70°F. What temperature does it show?
- 2 The red line moves from 60°F to 80°F. How many degrees warmer is it now?
- 3 Two thermometers show 40°F and 75°F. Which one shows a warmer day, and how do you know?