In order to give you some ideas on how to teach range in a math lesson, let me first of all recap what the term range means. Range is the difference between the lowest number and the highest number when looking at a set of numbers. For example, when looking at the numbers 1, 2, 3, 4, and 5, the range would would be 4. In order to find the range, you have to subtract the lowest number within the set of numbers from the highest number within the set—in this example, you would subtract 1 (the lowest number) from 5 (the highest number), which is why the result is 4.
To teach this, you could use pictures, where children color in the different numbers in different colors, highlighting the lowest number in a certain color (for example, green) and the highest number in a different color (for example, red). This will help them to visualize the process better.
Another teaching idea would be to give the students sets of numbers written on stones or cards and ask the students to arrange these numbers starting from the lowest number and going to the highest. Again, this will help the students to focus on number value, which is crucial for establishing range.
Having done this ranking activity a couple of times, the next step could then be to ask the children to remove the lowest number from this ranking activity and to count how many stones/cards they have left, which would be the range.