The video tutorial addresses common mathematical errors made by students. Jenny incorrectly solves an expression by not following the correct order of operations, known as BIDMAS, leading to a wrong answer. The correct approach is to perform multiplication before subtraction. Rehan makes a mistake in calculating the range of a set of numbers by subtracting the wrong values. The correct method involves subtracting the smallest number from the largest. Both examples highlight the importance of understanding and applying mathematical rules correctly.

Why was Rehan's calculation of the range incorrect?

Describe the correct method to find the range of a set of numbers.