Thanks so much. I know it was a simple question, especially after viewing all the complex ones on the forum. But, it's little things like that that are kind of skipped over, but become cummulative with other problem areas. A recent example was a quiz I found on Roman Numerals. You could know the meaning of them, but you would have to be instructed how to represent 9.
And your Galileo quote so appropos after my first meeting today with my 4th grader. I knew I could show her a whole lot she already knew, but did not realize how it was "packaged" on standardized tests, e.g., the property of zero.