The bottom of the paragraph on the left side states that “you cannot accurately apply ordinary annuity formulas to find monthly payments” for a Canadian mortgage because of semi-annual compounding. It then goes on to show the student how to use tables of semi-annual compounding factors to arrive at the exact monthly payment.
Duh!!! Guess where the tables of semi-annual compounding factors came from, a mathematical formula?
The purpose of the mathematics book should be to teach student mathematics and algebraic formulas and equations, not how to look up tables. We can train monkeys to look up tables. We should be teaching our children, solid, practical mathematics that will be of some use to them in life.