Marginalisation of heterodox economic ideas in economics departments ensures that for these ideas to endure, develop, and hopefully have influence, they must be taken up and understood by a wide range of academics in the larger field of social science. We hope to bring the debate on value theory to a wider audience by attempting to summarise, at least some of the main points of the debate, in less demanding language and through use of a less demanding mathematical technique than is conventionally employed. We shall attempt to simply, but accurately, present the Simultaneous and Dualistic Interpretation of Marx, the New Interpretation of Marx, the Temporal Single System Interpretation (TSSI) of Marx and the Value-Form position. Our purpose is not to suggest that these theories of value are either valid or invalid, but to stress how they imply very different views of how the economy works and, by implication, what issues we should focus on. Furthermore, and more controversially, we shall attempt to show how such different views fit with Marx's theory of the determination of value by labour-time and his comments on other theorists’ conceptions of value. To enable the interpretations to be clearly contrasted we shall employ a simple numerical example focusing on the question of accumulation and profitability.