Interpret negative numbers in context 9 - Reasoning

The question at hand involves understanding the concept of negative numbers in the context of temperature. Specifically, it revolves around finding the difference between 20°C and -8°C. A common mistake is to subtract the smaller number from the larger one without considering the direction of the number line. The initial answer suggests that the difference is 12°C, which is a misunderstanding of how negative numbers work. In reality, when we calculate the difference between two temperatures, we must account for the entire distance between the points on the temperature scale, not just the difference in their absolute values.

Therefore, to correct this misconception, we need to visualize the number line. The number -8 is 8 units below zero, while 20 is 20 units above zero. To find the total distance between -8 and 20, we must travel 8 units from -8 to reach 0, and then a further 20 units to reach 20. This gives us a total distance of 8 + 20, which equals 28 units. Hence, the correct difference between 20°C and -8°C is 28°C. This is a significant concept in number and place value, as it helps establish a solid understanding of how negative numbers relate to positive ones and how to interpret them in various contexts, such as temperature changes.