Determine the total fraction of money Kunle spent.

Kunle spends $\frac{5}{8}$ on books and $\frac{1}{4}$ on another item. To find the total spent, we add these fractions.
First, find a common denominator for 8 and 4, which is 8.

$$\frac{1}{4} = \frac{1 \times 2}{4 \times 2} = \frac{2}{8}$$

Now, add the fractions:

$$\text{Total spent} = \frac{5}{8} + \frac{2}{8} = \frac{5+2}{8} = \frac{7}{8}$$

The total pocket money can be represented as 1 (or $\frac{8}{8}$). To find the fraction left, subtract the total fraction spent from 1.

$$\text{Fraction left} = 1 - \frac{7}{8} = \frac{8}{8} - \frac{7}{8} = \frac{8-7}{8} = \frac{1}{8}$$

The fraction of his money left is $\frac{1}{8}$.