It is standard in the United States to report GDP growth and other economic data as annual rates. That is not the case in other countries where it is common to use quarterly growth rates. Rather than just picking up the number as reported in other countries, reporters should convert it to an annualized rate so that their audience in the United States will understand what is being reported. (This is the point, right?) Usually, just multiplying by 4 gets you there, although for higher growth numbers, it would be best to do it right and take the number to the 4th power.
The NYT got it wrong this morning in telling readers that the UK grew 0.3 percent in the first quarter. Its annual rate of growth was 1.2 percent.