Abstract
Chapter I: Introduction
        General Introduction
        What counts as numerical?
        Just numbers
        A brief review of number research
        Summary and aims
Chapter 2: General Methods
        Subjects
        Expectancy violation looking time paradigm
Chapter 3: Looking at Big Numbers
        Introduction
        Experiment 3.1. 3+1 = 4 v 8: Discrimination between large numbers
        Experiment 3.2: 2+2 = 4 v 8: Is updating hard?

Experiment 3.3: 4+4 = 4 v 8:Control for big number preference and updating

Experiment 3.4: 2+2 = 4 v 6: Can they do better?

Experiment 3.5: Working out the Object File system with dumbbells: 1+1 or 2+2?

Experiment 3.6: Clear dumbbells: Also 1+1, or maybe not?

Experiment 3.7: 4+1 = 4 vs. 5 vs. 8: The outer limits
Chapter 4: Conclusions
Accumulators and Object Files: Compatible theories?

Controlling for continuous extent: A potential confound

Future directions: The ecology and biology of guesstimating
References