The phrase "small number" means a small amount or count of something. It refers to a small quantity or a small group of things, usually indicating that there are not many of them. Full definition
Until then, the evidence for the existence of a new biological domain had been largely based on studies of small numbers of genes. (genomenewsnetwork.org)
The second issue is that a very small number of very large companies control the food chain, from seed to plate. (mercola.ebeaver.org)
Despite this, only small numbers of cells are dividing at any one time, so the treatment is not helpful in all cases. (brittonroadveterinaryclinic.com)