a person has 12004 coins of silver . how much would he need to add so that he can distribute equally among his 7 children in whole numbers ?
he would need to add one coin more so 12005 is fully divisible by 7 and each would get 1715 coins . so the correct answer is a
subtract(multiply(add(floor(divide(12004, 7)), const_1), 7), 12004)