Messfehler bei der Spannungsmessung eliminieren - Richtig messen an hochohmigen Schaltungen

How can you also correctly determine the voltage on high-value resistors? A possible solution for getting the correct result from two incorrect measured values ​​is given in this video, including a small arithmetic exercise. Shortly before the end of the video at 11:40 the points are missing in the figure for the values ​​of R2. Correct is 4.9MΩ or 4.5MΩ. 0:00 - What is it about? 0:46 - The problem 2:41 - Root cause research 5:19 - Walkthrough 8:32 - measure twice incorrectly, correct result 10:25 - Evidence by experiment