IQ is what a standardized IQ test measures. And there is no way such a person can effectively attend a standard IQ test - which is why this statement is pointless by definition.
And to connect this "low IQ" with having problems counting money is funny in multiple ways! First of all - counting anything is not what I would consider needing intelligence. Usually the opposite is correct - pertaining a boring task as counting is usually impaired by high intelligence.
And second of all - isn't the feat of "counting money" the root of most of mankind's biggest problems? Wouldn't it be more intelligent in fact trying to foster some of the conditions coming with this "disorder"?
Like approaching people open and friendly disregarding their dull and dismissive facial expressions and aura - tired from counting money very well all day long?