Numerical approximation

• How to Approximate a Hypotenuse Without a Square Root
  Estimate a hypotenuse without a square root using the larger side plus one third of the smaller side, and see the method's error.
• How to Calculate a Logarithm Without a Calculator
  Use logarithm laws for exact values, estimate by powers and familiar logs, or apply a convergent series to calculate logarithms by hand.
• How to Convert Radicals to Decimals Without a Calculator
  Estimate a radical without a calculator by bracketing it between perfect powers, testing decimal candidates, or using the square-root long-division method.