To find out what fraction of the total number of leaves Lee and Bee collected together, we need to first add their fractions.
Lee collects \( \frac{24}{100} \) of the total leaves, and Bee collects \( \frac{4}{10} \) of the total leaves.
First, we can convert Bee's fraction to a fraction with a denominator of 100 for easier addition:
\[ \frac{4}{10} = \frac{4 \times 10}{10 \times 10} = \frac{40}{100} \]
Now, we can add the two fractions together:
\[ \frac{24}{100} + \frac{40}{100} = \frac{24 + 40}{100} = \frac{64}{100} \]
Next, we can simplify \( \frac{64}{100} \):
\[ \frac{64}{100} = \frac{64 \div 4}{100 \div 4} = \frac{16}{25} \]
Therefore, the fraction of the total number of leaves that Lee and Bee collected together is \( \frac{16}{25} \).