The common definition of matter is anything that has mass and volume (occupies space). For example, a car would be said to be made of matter, as it has mass and volume (occupies space). The observation that matter occupies space goes back to antiquity.
The Radius of Mars is 3,389.5 km (About half of the radius of the Earth). Its circumference is 21,344 km (Not a big surprise, this is also about half of the circumference of the Earth). The volume of Mars is 1.63116 X 10 11 km 3 and the mass of Mars is 6.4169 x 10 23 kg. Although Mars is smaller than Earth its surface area (38% of earth) Is Almost identical to earth LAND space (Since there are no oceans on Mars). A common hoax is about the moon and Mars being equal in size. The hoax started back in 2003 when in august 27th Mars was in opposition to earth (Minimal distance) of about 55 Million KM.
The foot has 12 inches so there are 39.3700787402 inches per meter. Depending upon if you are measuring your garden, wallpaper, or landing a spacecraft on Mars, you can round to the appropriate number of digits.