Actually, good point. Since the question relates to something as HUGE as dark matter, being of the same order of magnitude makes it only 'slightly less'. At A level and uni (although to be fair I dropped out after a year) we were taught that getting an answer to the correct order of magnitude...
It's a third.
Get two pies. Give your friend a whole pie. Give yourself a third of a pie.
Are you getting 'far less' or 'slightly less' pie than your friend?
I've got to really thinking about when this experiment was first done in schools...
During the Apollo 15 mission, David Scott dropped a hammer and feather - and Galileo rolled cannonballs down a slope - but does anyone know who first thought up the most simple, mind-bending school lab...