[tex]\frac{6}{10}=0.6\\\\\frac{8}{100}=0.08\\\\\\\frac{6}{10}+\frac{8}{100}=0.6+0.08=0.68[/tex]
[tex]\frac{6}{10}=\frac{6\cdot10}{10\cdot10}=\frac{60}{100}\\\\\\\frac{6}{10}+\frac{8}{100}=\frac{60}{100}+\frac{8}{100}=\frac{60+8}{100}=\frac{68}{100}=\frac{68:4}{100:4}=\frac{17}{25}[/tex]