Ben and Ilene are having an argument: they are looking at a number line with a 0 on one end, and 1 million on the other end. The question is: where would 1 thousand be? Ben & Ilene have different insights into the problem: Ben says that 1,000 is a large number and so is a million, so it must be close to that side. Ilene says that 1 thousand is much smaller than 1 million, and it belongs closer to 0. Is either of them correct, or is one of them "more correct" than the other?
I've included 5 examples of sample work done by 4th grade students who answered this question, including an analysis of their thinking and the score they would earn on a 0 - 2 scale.
This "mystery" develops understanding of place value, magnitude of numbers and proportion in one simple questions.