The following is from https://en.wikipedia.org/wiki/Big_Bang_nucleosynthesis The era began at temperatures of around 10 MeV (116 gigakelvin) and ended at temperatures below 100 keV (1.16 gigakelvin). The corresponding time interval was from a few tenths of a second to up to 103 seconds. The temperature/time relation in this era can be given by the equation: tT2 = (0.74 s MeV2) × ( 10.75 / g∗ )1/2 where t is time in seconds, T is temperature in MeV and g* is the effective number of particle species. (g* includes contributions of 2 from photons, 7/2 from electron-positron pairs and 7/4 from each neutrino flavor. In the standard model g* is 10.75). Assuming g* = 10.75 simplifies this to tT2 = 0.74 s MeV2 I assume that what this means is that the product of time in seconds (t) and temperature squared (T2) in MeV2 will equal 0.74. However if I multiply the corresponding t and T2 values, I fail to get aything close to 0.74. (1) 10 MeV corresponds to "a few tenths of a second", and (2) 100 keV = 0.1 MeV corresponds to 1000 seconds. (1) is a bit ambiguous, so I arbitrarily substitute 0.3 seconds for "a few tenths of a second". Multiplying by 102 yields the product 30, not close to 0.74. For (2), multiplying 0.12 = 0.01 by 1000 yields the product 10, again not close to 0.74. What am I misunderstanding?