Using the Formula Reference
The Post Versalog 1460 is most effective when the operator understands both the mathematical formula and the scale relationship required to solve it.
This reference provides common formulas, the recommended Versalog 1460 scales and the general calculation sequence.
Basic Arithmetic Formulas
Multiplication
Formula:
A × B = Result
- Scales: C and D.
- Place the first factor on the D scale.
- Align the second factor using the C scale.
- Read the result from the D scale.
Division
Formula:
A ÷ B = Result
- Scales: C and D, or CI and D.
- Use CI when a reciprocal relationship improves efficiency.
- Confirm decimal placement through estimation.
Area Formulas
Rectangle Area
Formula:
A = length × width
- Scales: C and D.
- Ensure length and width use compatible units.
- Result is expressed in square units.
Circle Area
Formula:
A = πr²
- Scales: A, C/D or CF/DF.
- Square the radius using the A scale.
- Apply π using the appropriate arithmetic or folded scale relationship.
- Check the final magnitude.
Volume Formulas
Cylinder Volume
Formula:
V = πr²h
- Square the radius using the A scale.
- Multiply by π.
- Multiply by height using C and D.
- Report cubic units.
Rectangular Volume
Formula:
V = length × width × height
- Scales: C and D.
- Use continuous multiplication techniques.
- Confirm unit consistency.
Power Formulas
Square
Formula:
x²
- Scale: A.
- Locate the value on D.
- Read the square on A.
Cube
Formula:
x³
- Scale: K.
- Locate the value and read the cube relationship.
- Verify decimal placement carefully.
Trigonometric Formulas
Right Triangle Relationship
Formula:
sin θ = opposite ÷ hypotenuse
- Scale: S.
- Identify the known angle.
- Read the sine value.
- Apply the value in the remaining calculation.
Tangent Relationship
Formula:
tan θ = opposite ÷ adjacent
- Scale: T.
- Locate the angle.
- Read the tangent value.
Exponential Formulas
For formulas involving non-integer powers:
y = xⁿ
- Scale: LL.
- Select the correct LL range.
- Apply the exponent relationship.
- Verify the magnitude.
Formula Selection Method
- Write the formula before touching the slide rule.
- Identify every operation required.
- Select scales based on the operation.
- Estimate the answer.
- Perform the calculation.
- Verify the result.
Continue Learning
Continue to Versalog 1460 Glossary.