Pi Day is nearly upon us once more. The day is so named because it falls on 14 March, or rather, 3/14 for those who write dates in the month/day format, where these numbers are shared by the first three significant digits of the irrational mathematical constant pi (3.14...).
In 2021, Pi Day will fall on this upcoming Sunday, so we're marking the occasion with Matt Parker, who has found that some otherwise very competent calculators seem to be sneaking π into their computational results for one particular calculation.
The mystery for why the solution for 11⁶/13 is the only math for which Casio calculators will automatically incorporate π into its computational results has not yet been solved.