On the basis of findings from an experiment with 6-year-old children we show a proposal for a cognitive model of representational shifts in learning the number line. The findings from the experiment provide information on number line estimation - that is, translating a number to a spatial position on a number line. Though the experiment is a replication of an experiment done by Siegler and Ramani (2008) where they concluded with a logarithmic to linear shift, we could not find logarithmic representation of the results from any of our subjects. What we find is anchor points as important for improvement on learning the number line.