Do you know the answer?

Today in my chemistry class we began learning about the mole.  As an introductory lesson, I gave the students a little bit of the background of why scientists use moles and what moles are (not spots on your body or furry little creatures).  To accompany the notes that they took on some of the new vocab for the chapter they worked on an activity called "Rice-o-Rama" (I found this activity from a great resource whose creators seemed determined to come up with the cheesiest names that I am sometimes embarrassed to read aloud.)
 The object of this activity was to find two different ways to determine how many grains of rice there were in the dixie cup that I gave them without counting them all out individually. Many of them got to work right away and had no problem measuring out a few grains and finding their weight and using proportions to then determine how many total grains of rice they had in their cup.
After promptly completing their measurements, one group came up with a final answer of 2,000 grains of rice. Wide eyed and confused, they immediately asked me if I knew how many grains of rice they had.  Before answering their question, an idea flashed through my head.  The thought was "does it matter if I know the answer?".  The whole purpose of the activity was to introduce this idea to them, to throw a problem their way and have them analyze and solve it.  This group's question made me reflect on the type of teacher that I want to be.  I want my students to become independent thinkers and learners yet many of them seem very much content to be a small empty jug in which I pour my knowledge into them.  This is not what I want nor what I want for my students.
I think that sometimes we get pressured into "knowing" things instead of "learning" things.  As a teacher, I for one, constantly find myself answering questions instead of guiding to the answers.  This one instance in my classroom today challenged me to do things that will make me more of a guide rather than a person that my students perceive as an "all knowing being". This is definitely something that I want to work towards yet I'm unsure of how. I feel as though I took the first step by answering that group's question by saying, "Does it matter if I know the answer?  I'm more interested in what you guys think."