bc is ignoring scale option

Question

I can\'t figure out why bc tool sometimes ignores the scale option.

Here is an example:

> echo \'scale=2; 2.777 - 1.4744\' | bc
1.3026

Answer 1

From the bc(1) man page:

Unless specifically mentioned the scale of the result is the maximum scale of the expressions involved.

1.4744 has scale 4, so that's what happens to your expression.