HTML markup accuracy

Sometimes, it's the little glitches which create the most confusion. Take, for example, this article posted at PC World:

So how big is this IPv6?

Expressed in available addresses, it's so big that only math teachers might care. It is expressed several ways numerically: IPv4, the current one, has about 232 (about 4.3 billion) addresses. In comparison, IPv6 has 2128 (or 3.4 by 1038) addresses or it can be expressed as 340,282,366,920,938,463,463,374,607,431,770,000,000. UNH's InterOperability Lab guru for IPv6, Erica Johnson, said one theory she learned during her research was that Ipv6 has so many addresses that it compares to the number of grains of sand on the Earth. That is certainly more lyrical than the mathematical expression and might actually impress somebody (and is, of course, impossible to disprove). A spokesman at UNH's test lab added that the number of addresses can be expressed as "nearly" 340 undecillion. (Oddly, undecillion is defined as 1 followed by 36 zeros in the U.S., but by 66 zeros in Great Britain, according to Dictionary.com.)

If your eyes normally glaze over as soon as the numbers in the discussion rise above five, the preceding paragraph may not catch your eye as being misleading. Without the careful use of the proper markup (specifically, the superscript <SUP>), you get nonsensical things in your article like "232 (about 4.3 billion) addresses". For most forms of mathematics, 232 does not equal 4.3 billion! 2³² might be a bit closer.

I'm not a mathie, so I'll take their word for it that 2¹²⁸ can be expressed as 340,282,366,920,938,463,463,374,607,431,770,000,000.