Is 1/3+1/3 equal to 2/3?
Follow the rules of solving fractions:
1. To add fractions, the denominators must be equal.
2. Build each fraction (if needed) so that both denominators are equal.
3. Add the numerators of the fractions.
4. The new denominator will be the denominator of the built-up fractions.
5. Reduce or simplify your answer, if needed.
Hence: 1/3+1/3 =2/3 = 0.6666667
Source – Math Tuition