How to Become a Lightning Calculator

How to Become a Lightning Calculator by Anonymous author.

• Instantaneous Addition.
• How to Add Two Columns at Once.
• Multiplication.
• Accurate Interest.
• Equation of Payments.
• The Lightning Calculator’s Addition.
• Bank Discount.
• How to Make Change.
• Proof of Multiplication in Ten Seconds.
• The Canadian Interest Rule.
• Table of Transposed Numbers.
• Short Method to Find the Interest of a Given Sum.
• Interest Computations.