How are GDP rates calculated? We often hear that the GDP grew 2 % the past quarter, or something like that.

But we are also told the GDP grows annually about 2-3 % every year.

How can both be true? If the GDP grows 2 %  in just one quarter, surely annual growth rate should be closer to 8-10 %?
This question overlaps with the question: link to question on quarterly/annual GDP.

Since you are referring to news commentary, I just want to add that the standard in the United States is to quote annualised quarterly GDP figures (e.g. 2.0% annualised roughly equals 0.5% on the quarter), while European countries (e.g., Germany) often quote the non-annualised quarterly growth rate. (These are the conventions used by the national statistical agencies when quoting growth rates, and the business press usually follows the local convention when reporting on the results.) This difference sometimes can cause confusion in international comparisons.