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

as Carl pointed out, if you check man page, you can find that line. it is about expression explanations. subtraction won't read scale variable. If you want to get the expected result (1.30), you could:

kent$  echo 'scale=2; (2.777 - 1.4744)/1' | bc 
1.30

/ operation will read scale variable.