Blowing out candles on a cake is a birthday tradition.
People put one candle for each year of your age. You make a wish and blow them all out in one puff.
More facts about Birthday Party
A birthday marks the special day you were born.
Balloons float when they are filled with a light gas called helium.
People sing the 'Happy Birthday' song all around the world.
In Vietnam, some families celebrate a baby's first full month.
The most candles ever lit on one birthday cake was over 72,000.