• bandwidthcrisis@lemmy.world
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    1 year ago

    For C to F, double it, subtract a 10th of the result, add 32.

    E.g. 20 double is 40, minus a 10th is 40-4, so 36, add 32 giving 68.

    If you ignore fractions when you take the tenth, you can do it in your head to be pretty close.

    17, x2 is 34 a 10th is about 3, so 34-3 is 31, +32 is 63 (actually 62.6).