One billion is usually considered a big number, what’s a way to make it look small?

Inflation.
Have fun buying the bare minimum of groceries with that billion

One billion femtograms weighs less than one gram.

Count the number of times women said “eww” to themselves when they saw you.

Take a deep breath. You just inhaled approximately 2.4 × 10^22 molecules of gas. That is 24,000,000,000,000,000,000,000. Or 24 trillion billions (I think).

1×10^9