Number cognition
From our very early school years we start to realize that numbers govern much of our life. The symbolic mathematical competence that characterises much human activity is grounded in phylogenetically older systems that allow approximate, but behaviourally adaptive, estimates of numerosity. During bio- logical evolution these rudimentary mathematical abilities might have been crucial for survival and adaptation. In this special issue, we offer an overview of some promising lines of ongoing research on number processing in the brain. The results provided by such a wide variety of lines of inquiry, ranging from the perception of numerosity to the performance of different types of mathematical opera- tions with Arabic numbers and the use of mathematical symbols and operands, renew and advance the understanding of math tools that biological and cultural evolution have jointly forged in our brains.