Multiplication

• 1). Slide the middle section of the slide rule so the 1 on the "C" scale lines up with the first number you are multiplying on the fixed "D" scale. The scales "A", "B", "C" and "D" are labeled on the left side of the slide rule. For an example we will calculate 4 X 2. To do this, move the "C" scale so the 1 lines up with the 4 on the "D" scale.
  
  
• 2). Find the number you are multiplying by on the "C" scale without moving the slide rule. For our example we need to find the number 2 on the "C" scale.
  
  
• 3). Determine which number on the "D" scale lines up with the number you are multiplying by on the "C" scale, this number is the product of the two numbers being multiplied. In our example the 2 on the "C" scale should be lined up with the 8 on the "D" scale giving us 4 X 2 = 8.
  
  

Division

• 1). Slide the middle section of the slide rule so the number you are dividing by on the "C" scale lines up with the number you are dividing on the "D" scale. For an example we will calculate 6/2 by lining the 2 on the "C" scale with the 6 on the "D" scale.
  
  
• 2). Find the number 1 on the "C" scale.
  
  
• 3). Determine which number on the "D" scale lines up with the number 1 on the "C" scale: this is the quotient of the numbers being divided. For our example the number 3 on the "D" scale should be lined up with the number 1 on the "C" scale.