Hello,
I know that {cheb} is defined as "roughly 5 lbs" in Okrand's Usenet
message. And the BoP poster mentions the weight of {cheb'a'} in the
following relationship:
375,000 cheb'a' = 8.7 KT
I remember reading that 1 {cheb'a'} might be 9 {cheb},
It is commonly assumed that a {cheb'a'} is 9 {cheb}, but Dr. Okrand did not explicitly state this. He only said that "most units" of measure had forms with {-'a'} added to mean 9 times. The report of that conversation is here:
but no matter
what I calculate, I don't get it – so where's my error?
You are most certainly using the wrong definition of "KT". If you use an American "short" ton and assume a factor of 9, you get:
8.7 KT = 8.7 × 1000 × 2000 lb = 17,400,000 lb = 375,000 × 46.4 lb = 375,000 × 9 × 5.156 lb (2.339 kg)
This is close to the stated value of "around five pounds (2.25 kg or so)". If you go in the other direction, assuming a value of 5 lbs:
375,000 × 9 × 5 lb = 16875000 lb = 8.43 KT
Or if you start with the given value in kg:
375,000 × 9 × 2.25 kg = 7593750 kg = 16741353 lb = 8.37 KT
These are within a few percent of the stated value of 8.7 KT. Presumably, the difference is between the gravity on Qo'noS and the gravity on Earth, since "pounds" are a unit of weight, not mass. The original msn message in which {cheb} appears refers to it as a unit of weight, but gives a conversion to kg (but presumably under Earth or near-Earth gravity).