If we didn't have rational numbers we would not be able to do anything with decimals or fractions. Such as taxes or whenever you buy something. Giuseppe Peano was born on August 27, 1858 and died on April 1932.He was born and raised on a farm in Spinetta , Italy.He attended the University of Turin in 1876 and graduated in 1880 with high honors.He was appointed extraordinary professor of infinitesimal calculus at university of Turin in 1890.In 1908 he made the fifth final edition of the formulalrio mathematicoHe was also Promoted to commendatore of the crown of Italy in 1921 How do we use rational numbers? Why do we need rational numbers? The History Of Rational Numbers What is a rational number? A rational number is any number that can be expressed as a quotient or fraction of two integers.Rational numbers cannot be equal to zeroNumbers that are not rational are called irrational numbers Number As a fraction Rational? 5 5/1 Yes 1.75 7/4 Yes .001 1/9 Yes ... 5/4 NO It was named in 1895 by Giuseppe Peano. We use rational numbers with gradients of hills, prices of items, sales with percents off, and many other things. Why did they need it when discovered? Giuseppe Peano used the space-filling curve to find rational numbers. He used it to show that a continuous curve cannot always be enclosed in a small region.