490 was an unwieldy number in those days, even for educated folk: Arabic numerals hadn't been invented yet.
The universal acceptance of Arabic numerals was not until the 9th century, however regionally the Arabian Peninsula had used them for quite some time. This can be seen in Saracen-Christian translations of the bible in the time period you're referring to. Most of the numbers we use today had been already 'invented' around 400-500 years before Jesus was around. Ways and cultures(including arabic numerals) of the Arabian Peninsula weren't even introduced to europe/asia minor until a Saracen empire began to emerge and expand.
Certainly other numeral systems in use in Jesus' time (Babylonian, Greek, Roman, Abjad, ...) were total hell for the sort of arithmatic problems we give these days to grade school students.quadz
Well, not to try to go off topic here but I will be the first to admit - I AM NOT SMARTER THAN A 5th GRADER!!!!
A & E will be showing the documentary "Jesus Camp" this coming Sunday/Monday. I haven't seen it, but the previews looked interesting. And these kids are so young....