Operações com Frações – Subtração

Synopsis: this time is explained as performs subtraction of fractions; First of fractions with the same denominator and then with different denominators, using again the idea of ​​equivalent fractions. Examples and exercises on the magic square, involving these operations with fractions were created.
Source: Portal of Mathematics.
URL: http://matematica.obmep.org.br/index.php/modulo/ver?modulo=28