I've always found using the unit seconds to be the easiest way to convey the scale of billions vs millions. 1 billion seconds =~ 32 years 1 million seconds =~

I've always found using the unit seconds to be the easiest way to convey the scale of billions vs millions. 1 billion seconds =~ 32 years 1 million seconds =~ 12 days Edit: mikeash beat me to it ;)