Always funny to see the objections of new hires without finance experience to the use of floating point for pricing. It’s more related to the inherent inaccuracy of any pricing model though, rather than clients not caring about pennies.
"The sum of these values need to equal the sum of these values"
In that case you'd then needs to avoid
"sum_a == sum_b"
and use instead
"abs(sum_a - sum_b) < SOME_SMALL_VALUE"