Please help me understand how to solve the following question The national debt is around $19 trillion dollars And the new tax reform law, from GSA

Please help me understand how to solve the following question

The national debt is around $19 trillion dollars 

And the new tax reform law, from GSA adds $2.1 trillion to the national debt in 4 years

What dollar increase, if it does occur, is this on an annual basis, calculated using scientific notation.

Express the answer in scientific notation.