PHP Manual: bcsub
bcsub
Description
string bcsub ( string left_operand, string right_operand [, int scale] )
Subtracts the right_operand from the
left_operand.
Parameters
left_operandThe left operand, as a string.
right_operandThe right operand, as a string.
scaleThis optional parameter is used to set the number of digits after the decimal place in the result. You can also set the global default scale for all functions by using bcscale().