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Everyday maths 1
Everyday maths 1

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5.1 Reading temperatures

Many things have to be stored or used in a particular temperature range to be safe. Temperature is measured with a thermometer.

Thermometers for different uses show different ranges of temperatures.

Take a look at the following example, which shows two types of thermometer.

Case study _unit3.5.1 Example: Reading thermometers

What is the temperature shown on each thermometer below?

Described image
Figure _unit3.5.2 Figure 37 Reading the temperatures

Method

On the first thermometer, there are four divisions between 20 and 30, so the divisions mark every two degrees (22, 24, 26, 28). The reading is at the second mark after 20, so the temperature is 24°C.

On the second thermometer, the temperature is at the mark halfway between 37 and 38, so it’s 37.5°C.

What temperature do you think it is today? If you have a thermometer, check the temperature outside; if you don’t, you could use an online resource such as the BBC Weather pages [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] or your mobile phone to find the temperature near you.

Now try the following activity. Remember to check your answers once you have completed the questions.

Activity _unit3.5.1 Activity 12: Reading thermometers

What temperature is shown on each of these thermometers?

  1. Described image
    Figure _unit3.5.3 Figure 38 A thermometer
  2. Described image
    Figure _unit3.5.4 Figure 39 A thermometer
  3. Described image
    Figure _unit3.5.5 Figure 40 A thermometer

Answer

  1. Each mark on the thermometer represents 20°C and the needle is at the mark below 400, so the temperature is 380°C.
  2. The reading is on the mark halfway between 38°C and 39°C, so the temperature is 38.5°C.
  3. Each mark represents 2°C, so the temperature is 16°C.