1) Linda -- would you share those geogebra files with me so I can download please?
2) I was struck by a remark you made in another thread that you avoid fractions and try to use decimals where possible. I see that bias in your first applet. I'm not sure that trying to get students to strengthen their understanding of how the comparative sizes of different fractions by comparing them to decimals is going to make the fractions more mearningful. To me decimals tend to be strings of numbers whereas fractions are more 'thinkable' units.
An approach I might find more usefbul is to use 0, 1/2, and1 as signposts. I think I want my kids to be able to estimate a new fraction in a more general way -- in terms of its proximity to one of those markers.
1) How can you describe (verbally) 1/2 in terms of the markers 0, 1/2 and 1 (shown on a number line)?
2) Can you be more specific?
closer to 0?
closer to 1/2?
a little more than 0?
a little less than 1/2?
How (intuitively) do you know that? How (mecahnically) could you show it?
2) if the space between 0 and 1 is divided into fourths, where would you put 1/3 now?
less than 1/2 but more than 1/4
How did you make that decision?
I think this leads later to comparing fractions & percentages than then to bringing in decimals as well.