Compare temperature: negative and positive number comparison

Students compare temperatures above and below zero and explain which one is warmer or colder.

• Positive readings: 35 °C is warmer than 10 °C.
• Readings around zero: −1 °F is colder than 0 °F, which is colder than 1 °F.
• Two negative readings: −18 °C is colder than −10 °C, even though 18 is bigger than 10.

This is exactly standard 6.NS.C.7.b: write, interpret and explain statements of order for rational numbers in real-world contexts. It also uses 6.NS.C.5, positive and negative numbers for quantities above and below zero.

Draw a vertical number line or a simple thermometer from −20 to 40 before you start. For each problem:

• Mark both temperatures on the line.
• Higher on the line means warmer; lower means colder.
• Say the answer as a full sentence, for example −18 °C is colder than −10 °C.

Page two has the answers with a short reason for each, so your child can check their own sentence against it.

• Treating −18 as bigger than −10: the bigger digits fool kids. Point to the thermometer: further below zero is colder.
• Thinking zero means no temperature: 0 °F is a real reading, and it is warmer than −1 °F.
• Reading the question backwards: the question asks which is colder and kids tick the warmer one. Underline the key word first.

Next, convert between Celsius and Fahrenheit in the following sheet of this series.