The 16-place result is `2.221441469079183`. From this we see that a 5-significant-digit approximation would be `2.2214`. The result from `3.14//1.414` is `2.2206506...` . The error is about `0.0008`, which means the third decimal place cannot be assumed accurate, so the answer (as an approximation to `pi//sqrt(2)`) has only three significant digits, namely `2.22`.