Upper panel: cumulative (or the integral) number counts at 450 μm. Our results derived from the de-blended catalogue in the COSMOS field are plotted as red stars (filled red stars: our number counts above the flux cut; empty red stars: our number counts below the flux cut). Error bars on the red stars only represent Poisson errors. The lines show the predicted number counts from various models and simulations (including SIDES, EGG, GALFORM, and the EAGLE hydrodynamic simulation). The empty diamonds are previous results based on JCMT SCUBA-2 observations. Lower panel: differential number counts at 450 μm.