[tex](1 \frac{3}{9} + \frac{6}{9} + 1) \div 3 = ( \frac{12}{9} + \frac{6}{9} + \frac{9}{9} ) \div 3 = \frac{12 +6 + 9 }{9} \times \frac{1}{3} = \frac{27}{9} \times \frac{1}{3} = 1[/tex]