Number of cubes = 1,000,000
Side of each cube = 1 inch
The cubes are stacked on top of each other to make a tower
Height of the tower = Number of cubes × Side of each cube
⇒ Height of the tower = 1,000,000 × 1
⇒ Height of the tower = 1,000,000 inches
Hence, the tower is 1,000,000 inches high