Volume of a Cylindrical Block

• 1). Determine the shape of the plastic block. If it's cylindrical, follow the steps outlined under this section. Rectangular, triangular and spherical blocks are in the following sections (2 to 4).
  
  
• 2). Measure the height of the cylinder and its radius. (The radius is one-half of the distance across a circle, so measure the distance across the top of the cylinder and divide it by 2.)
  
  
• 3). Punch the radius into your calculator and hit the "square" button to multiply the value by itself. Multiply your answer by the height of the cylinder and the number pi. You can retrieve the number pi by pushing the pi button on your calculator, or use 3.142 as an approximation. For example, if the height is 10 cm and the radius is 2 cm, the volume = 3.142 (2 x 2) (10) = 125.7 cubic cm.
  
  

Volume of a Rectangular Block

• 1). Measure the height of your block.
  
  
• 2). Measure the width and length of your block.
  
  
• 3). Multiply the length by the width and height. For example, if the height is 2 cm, the width is 4 cm and the length is 6 cm, the volume = 2 x 4 x 6 = 48 cubic cm.
  
  

Volume of a Spherical Block

• 1). Measure the radius of your spherical block. The radius will be one-half of the distance across the sphere. If the diameter of the sphere is 6 cm, for example, the radius is 3 cm.
  
  
• 2). Cube the radius (multiply it by itself twice). If the radius is 3 cm, for example, you would multiply 3 x 3 x 3 to get 27. Most calculators will have a y^x button you can use to take the cube of any number automatically.
  
  
• 3). Divide your answer by 3, then multiply it by 4 (or just multiply it by 0.75). for example, 27 divided by 3 is 9, and 9 multiplied by 4 is 36.
  
  
• 4). Multiply your answer by pi to get the volume of the sphere. In the preceding example, then, the volume of the sphere is 3.142 x 36, or 113.1 cubic cm.
  
  

Volume of a Triangular Block

• 1). Measure the length of the triangular prism/block, then measure its height and width.
  
  
• 2). Multiply the length by the height and width. If the length is 10 cm, the height is 2 cm and the width is 4 cm, for example, you would multiply 10 x 2 x 4 = 80 cubic cm.
  
  
• 3). Divide your answer by 2 to get the volume of the block. For example, 80 cubic cm divided by 2 is 40 cubic cm.