the unit digit in the product ( 891 * 781 * 912 * 463 ) is :
"explanation : unit digit in the given product = unit digit in ( 1 * 1 * 2 * 3 ) = 6 answer : c"
subtract(multiply(multiply(multiply(891, 781), 912), 463), subtract(multiply(multiply(multiply(891, 781), 912), 463), add(const_4, const_4)))