WASHINGTON (AP) -- Instead of "Hail to the Chief," President Barack Obama most likely heard strains of "Happy Birthday" this weekend.<br />
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Obama, who turned 52 on Sunday, spent part of the day at the Camp David presidential retreat in Maryland.<br />
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The White House said little about how he celebrated.<br />
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The president played golf Saturday with friends from his days in Hawaii and Chicago. Some of them joined him at Camp David.<br />
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Obama said nothing upon his afternoon return to the White House.<br />
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His week ahead includes a trip Tuesday to Phoenix to discuss plans to help homeowners, an appearance on "The Tonight Show" with Jay Leno and visit Wednesday with troops at Camp Pendleton in California.<br />
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He also has a White House meeting Thursday with the prime minister of Greece.
