Reading Temperature Scales

Overview

Lesson 5 of 7 in Measuring Tools and Units. Students read, compare and record temperatures in degrees Celsius, using thermometer scales and realistic weather data from New Zealand locations.

Learning intentions

• WALT read temperatures from a thermometer scale.
• WALT record temperatures using degrees Celsius and the symbol °C.
• WALT compare and order temperatures from coldest to warmest.
• WALT explain how temperature changes above and below zero.

Success criteria

• I can identify degrees Celsius and use the symbol °C.
• I can read intervals and temperatures from a thermometer scale.
• I can compare and order temperatures.
• I can explain whether a temperature has increased or decreased.

Curriculum links

• Number and Algebra: use whole numbers, including negative numbers where appropriate, to compare and order values.
• Measurement: read and interpret scales using appropriate units, including degrees Celsius.
• Statistics: interpret temperature information presented in tables or weather reports.
• Mathematical processes and competencies: communicate mathematical thinking, use representations, and reason about change.

Lesson structure (30 minutes)

1. 0–4 minutes – Temperature hook and prior knowledge

Open with the temperature hook slide showing two contrasting New Zealand weather scenes, such as a frosty morning and a sunny beach. Ask: “Which place is colder, and how could we prove it?” Invite students to share where they have seen temperature recorded and introduce the unit degrees Celsius, written °C.

2. 4–10 minutes – Model reading a thermometer

Display the thermometer modelling slides and use a large physical thermometer or interactive thermometer. Think aloud: first identify the zero line, then count the equal intervals, then read the level of the liquid. Model temperatures above zero and, if suitable for the class, one or two temperatures below zero. Emphasise that numbers increase as we move up the scale and decrease as we move down.

Model recording answers correctly: 8°C, 0°C and −3°C. Clarify that 8°C is warmer than 3°C, while −3°C is colder than 0°C.

3. 10–14 minutes – Guided comparison

Display the guided comparison slides with pairs such as 6°C and 11°C, 0°C and −2°C, and −4°C and 2°C. Students show which temperature is warmer using hand signals or mini whiteboards, then explain their reasoning to a partner.

Provide guided examples: “The temperature moved from 4°C to 9°C, so it became warmer by 5 degrees.” For students consolidating the concept, focus first on temperatures from 0°C to 20°C.

4. 14–23 minutes – Weather temperature activity

Distribute the thermometer and weather temperature worksheet. Students work in pairs, then complete selected questions independently. They read illustrated thermometer scales, write each temperature with °C, compare pairs using “warmer than” or “colder than”, and order five New Zealand weather temperatures from coldest to warmest.

Use a current or prepared example based on the New Zealand weather activity slides. Refer to a few MetService town or city temperatures if available, but avoid requiring students to copy large amounts of information. Circulate and ask: “What is one interval worth?” and “How do you know this temperature is colder?”

5. 23–27 minutes – Temperature change challenge

Pairs discuss two examples from the worksheet, such as a morning temperature of 7°C and an afternoon temperature of 15°C. They calculate or describe the change using a number line. Students who are ready investigate a daily high and low: “What is the difference between −2°C and 9°C?” Accept a number sentence, number-line explanation or oral explanation.

6. 27–30 minutes – Plenary and exit check

Return to the plenary and success criteria slide. Ask students to answer orally or on a whiteboard: “Which is colder: −1°C or 3°C? How do you know?” Students self-assess against the success criteria and complete one final statement: “When the temperature changes from ___°C to ___°C, it becomes warmer/colder by ___ degrees.”

Resources

• the temperature reading slide deck
• the thermometer and weather temperature worksheet
• Large physical thermometers
• Interactive thermometer for teacher modelling
• Mini whiteboards and pens
• Number lines, including a large floor or display number line
• Prepared weather cards showing New Zealand temperatures
• Projector or interactive whiteboard
• Optional current weather information from MetService

Assessment

• Observe whether students count scale intervals accurately and record the °C symbol.
• Listen to partner explanations when students compare temperatures, noting whether they use the number line or scale correctly.
• Check worksheet responses and the final temperature-change statement for misconceptions, especially confusing warmer and colder or reading intervals inaccurately.

Differentiation

• Support learners with large physical thermometers, highlighted scale intervals, colour coding for warmer and colder, and a visible number line. Begin with positive whole-number temperatures before introducing negative values.
• Provide guided examples, partially completed scales and oral rehearsal: “I can see ___ intervals; each interval is ___ degrees; the temperature is ___°C.”
• Use dyslexia-friendly resources: large print, clear sans-serif font, uncluttered weather cards, strong contrast, colour coding and reduced written instructions. Allow students to explain answers orally or point to a scale.
• Extend confident learners by asking them to calculate changes across zero, compare daily high and low temperatures, or create a short temperature report using at least four readings.