3rd year of secondary education.





Operations with fractions

Rational numbers.


Fractions, decimals and percentages.

This unit introduces the concept of rational numbers based on the concept of fractions of whole numbers.

In the first section we explain the concepts of fractions and equivalent fractions as well as how to find a common denominator in order to compare fractions.

In the second section we look at how to add, subtract, multiply and divide fractions.

In the third section we look at other ways of representing fractions as decimals and focus on the concept of rational numbers.

The final part of the unit gives examples of how to apply fractions and percentages to everyday situations.

  • To understand what a fraction is.
  • To be able to compare fractions.
  • To carry out different arithmetic operations with fractions.
  • To be able to express a fraction as a decimal.
  • To understand which decimal numbers are rational numbers.
  • To use percentages in different operations.

  Ángela Núñez Castaín
Spanish Ministry of Education. Year 2001

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