“Mathematics maybe, but not money”

Purpose The purpose of this paper is to consider and compare different ways of using numbers to value aspects of nature-beyond-the-human through case analysis of ecological and natural capital accounting practices in the UK that create standardised numerical-economic values for beyond-human natures. In addition, to contrast underlying ontological and ethical assumptions of these arithmetical approaches in ecological accounting with those associated with Pythagorean nature-numbering practices and fractal geometry. In doing so, to draw out distinctions between arithmetical and geometrical ontologies of nature and their relevance for “valuing nature”. Design/methodology/approach Close reading and review of policy texts and associated calculations in: UK natural capital accounts for “opening stock” inventories in 2007 and 2014; and in the experimental implementation of biodiversity offsetting (BDO) in land-use planning in England. Tracking the iterative calculations of biodiversity offset requirements in a specific planning case. Conceptual review, drawing on and contrasting different numbering practices being applied so as to generate numerical-economic values for natures-beyond-the-human. Findings In the cases of ecological accounting practices analysed here, the natures thus numbered are valued and “accounted for” using arithmetical methodologies that create commensurability and facilitate appropriation of the values so created. Notions of non-monetary value, and associated practices, are marginalised. Instead of creating standardisation and clarity, however, the accounting practices considered here for natural capital accounts and BDO create nature-signalling numbers that are struggled over and contested. Originality/value This is the first critical engagement with the specific policy texts and case applications considered here, and, the authors believe, the first attempt to contrast arithmetical and geometrical numbering practices in their application to the understanding and valuing of natures-beyond-the-human.