How many pennies would it take to cover a wall?

To determine how many pennies it would take to cover a wall, you first need to know the dimensions of the wall and the size of a penny. A penny has a diameter of about 1.9 cm. For example, if a wall is 2 meters by 3 meters (or 200 cm by 300 cm), the wall area is 60000 cm². The area of a penny is approximately 2.8 cm², so you would need about 21,428 pennies to cover that wall.