Comment by rsfern
3 years ago
The scale factor is 9/5, which is close enough to 2 that the precision is fine for casual conversion (weather report, discussion of boiling tea on the web, …)
3 years ago
The scale factor is 9/5, which is close enough to 2 that the precision is fine for casual conversion (weather report, discussion of boiling tea on the web, …)
Definitely not. Say, 86F to C. 86F is 30C, but dividing the F by 2 would give you "43C", which converts to 109F. That is not a trivial difference.
You forgot to subtract 32 first. Then you get 27. Or in this case, 54 happens to be evenly divisible by 9, so doing the exact conversion is relatively convenient (divide by nine, multiply by five).