How Big Is A Billion?

If I gave you $1,000 a day, seven days a week, how long would it take you to collect 1 billion dollars? (Assume that you spend none of the money, and collect no interest on it.)

answer: 2,737.85 years (2,737 years, 10 months, 7 days)

This means that if the payments had begun on the first day of the common era (January 1, year 1 on the Gregorian calendar), it would be November 7, 2738 before the $1 billion would accumulate.

The calculation

1,000,000,000 / 1,000 gives us the number of days.
In this case, 1 million. Dividing 1 million by 365.25 (roughly the number of days per calendar year) gives us the number of years

We are Spending $4-to-5 Billion a week in Iraq.