You can add as many fractions together as you want, but you have to make sure they all have common denominator. (or common bottom number)
For example, say you had:
$$\frac{3}{4} + \frac {1}{2} + \frac{5}{8}$$
First, we have to make all these number have a common denominator. To do this, multiply the top and bottom of the first fraction by 2, and the top and bottom of the second fraction by 4.
$$\frac{3\times2}{4\times2}+\frac{1\times4}{2\times4}+\frac{5}{8}$$
$$\frac{6}{8} + \frac{4}{8} + \frac{5}{8}$$
Great! Now all these bottom numbers are the same, so we just add the top numbers, and keep the 8 on the bottom.
$$\frac{6+4+5}{8}$$
$$\frac{15}{8}$$
or you could write this as:
$$1\frac{7}{8}$$
You can add as many fractions together as you want, but you have to make sure they all have common denominator. (or common bottom number)
For example, say you had:
$$\frac{3}{4} + \frac {1}{2} + \frac{5}{8}$$
First, we have to make all these number have a common denominator. To do this, multiply the top and bottom of the first fraction by 2, and the top and bottom of the second fraction by 4.
$$\frac{3\times2}{4\times2}+\frac{1\times4}{2\times4}+\frac{5}{8}$$
$$\frac{6}{8} + \frac{4}{8} + \frac{5}{8}$$
Great! Now all these bottom numbers are the same, so we just add the top numbers, and keep the 8 on the bottom.
$$\frac{6+4+5}{8}$$
$$\frac{15}{8}$$
or you could write this as:
$$1\frac{7}{8}$$