Or, we could change the starting age band for each year.<p>Perhaps July is simply a poor cutoff.<p>Shift starting age by 1-2 weeks a year and class size would change little, but you could quickly alter the age bands for each grade level.<p>Or perhaps we use 1&#x2F;2 year bands.  So, some students start in fall and graduate in spring like now and other start in January and graduate in December.  Which also means someone could skip or fail 1&#x2F;2 a year.<p>PS: The point being the current system is hardly the only way to approach mass education.