On standard calculators, fractional problems can be solved by first converting the fractions into decimals, then converting the solution back into a fraction. Scientific calculators usually have the ability to enter fractions without having to use decimals.

A fraction is converted to a decimal by dividing the numerator by the denominator on the calculator. For example, 5/8 is converted by first entering 5, then the Divide key, then the 8 key and finally the Equal key. The calculator then gives the solution of 0.625. Once both fractions are converted to decimals, the problem can be solved on a standard calculator. For example, the problem "5/8 + 1/5" is converted to "0.625 + 0.2," to which the solution is 0.825.

Math problems that initially use fractions in the equation usually require the solution to be in fractional form. Therefore, the solution presented by a standard calculator in decimal form has to be converted. To convert a decimal to a fraction, the decimal first should be placed as the numerator in a fraction that uses a denominator of one. Then, both the numerator and denominator are multiplied by the same factor so that the numerator becomes a whole number. For example, 0.125/1 is converted to 125/1000 by multiplying both the numerator and the denominator by 1000. The fraction can then be simplified by dividing both the numerator and the denominator by their greatest common factor. Using the factor of 125, 125/1000 is simplified to 1/8.