Calculator
Approximations
References
Celcius to Fahrenheit
A) Celcius to Fahrenheit aproximation table for the trick
- Start with 04 deg C, then add 12 until you get close to the the deg C you wish to convert.
(max 40 C)
- Then reverse the digits of C to get deg F.
(at 40 C you have to reverse and add 100 deg F. Example: 40 reversed to 04 + 100 = 104)
| Celcius | reversed | Fahrenheit |
|---|
| 04 + 0x12 = | 04 | => | 040 |
| 04 + 1x12 = | 16 | => | 061 |
| 04 + 2x12 = | 28 | => | 082 |
| 04 + 3x12 = | 40 | => | 104 |
B) F~(C) = C x 2 + 30
Fahrenheit to Celcius aproximations
A) Use C to F table above to generate the closest F, and work backwards.
B) OR use this aproximate formual: C~(F) = F/10 + F/2 - 20
C) OR use this table:
| Fahrenheit | | trick | => | Celcius |
|---|
| 40 - 1x20 = | 020 minus 2 | = | 020 F / 10 - 1x10 | => | -8 |
| 40 + 0x20 = | 040 minus 1 | = | 040 F / 10 + 0x10 | => | 04 |
| 40 + 1x20 = | 060 plus 1 | = | 060 F / 10 + 1x10 | => | 16 |
| 40 + 2x20 = | 080 plus 2 | = | 080 F / 10 + 2x10 | => | 28 |
| 40 + 3x20 = | 100 plus 4 | = | 100 F / 10 + 3x10 | => | 40 |
graph
