the unit digit in the product 3421 * 6721 * 4584 * 6784 is ?
"unit digit in the given product = unit digit in 1 * 1 * 4 * 4 = 6 answer is c"
subtract(multiply(multiply(multiply(3421, 6721), 4584), 6784), subtract(multiply(multiply(multiply(3421, 6721), 4584), 6784), add(const_4, const_4)))