Place food in the microwave, then close the door. The microwave cannot function unless the door is closed.
Choose the microwave power setting by turning its top knob. The microwave's power is on a 1 to 10 scale, with 10 being the hottest. For items that need reheating, turn the knob to 2 or 4. For items from the freezer, such as waffles or other snack foods, turn the knob to 5 or 7. Only use 8 and above if the food is completely frozen and takes a while to cook, or when a recipe or cooking instructions require it.
Choose an appropriate time by turning the other knob. Point the arrow on the knob to the number of minutes you want your food to cook. The knob will slowly turn until it hits zero and dings.
Complete the cooking process by taking the food out when the time runs out. Leave the food in the microwave for a couple of minutes, if the food was heated for 5 minutes or more.