He doesn't grasp that a disease 10x more deadly than flu (0.1% vs. 1% in his example) means 10x more deaths.
If flu normally kills 30,000 in an average year in the US (30 million infections times 0.1%), that means 300,000 deaths (30 million infections times 1%).
But hey, no big deal to Rush Limbaugh, because 300,000 dead isn't the old higher estimate of 3% (30 million infections times 3% = 900,000 deaths).
Incredible.