那就是 9 billion 刀了。有人知道一个billion的100刀的钞票占多大的地儿吗？看下面：

Using the dimensions he gives
6.14 in x 2.61 in x 0.0043 in
one billion one-dollar bills would occupy a volume of
68,909,220 cubic inches
= 39878 cubic feet

This could fit in a cube of dimensions 34.16 feet on a side. In other words, it would take the space of a large house filled floor-to-ceiling with bills.

The largest bill in circulation today is the $100 bill. If we wanted to store the billion dollars more compactly with $100 bills, it would occupy
689092 cubic inches
= 398.8 cubic feet

This would occupy a cube of dimensions 7.36 feet on a side. It would easily fit in a small room, as xjavabotx said.

A small box used by moving companies holds about 1.5 cubic feet; so for a billion dollars in $100 bills, you would need about 266 small moving boxes (all very tightly packed).

If you want to carry a billion dollars, you're better off taking priceless jewels. Paper bills are too bulky, and gold is too heavy.

Gold today is $881 per troy ounce, or $803 per ounce avoirdupois. A billion dollars in gold would weigh 38.9 tons (U.S.).