碗 is both a noun (bowl) and a measure word for bowls of food: 一碗饭 (a bowl of rice), 两碗面 (two bowls of noodles). 洗碗 means "to wash dishes" — not just bowls.
culture
In Chinese dining etiquette, you should never stick your chopsticks upright in a bowl of rice — it resembles incense sticks at a funeral and is considered very bad luck.
