On a hot day, Mackenzie poured 7 3/10 buckets of water into a plastic wading pool. A few minutes later she added another 6/10 of a bucket. How much water did Mackenzie pour into the pool?

To find out how much water Mackenzie poured into the pool, we need to add the two amounts together: \(7 \frac{3}{10}\) buckets and \(\frac{6}{10}\) of a bucket.

First, we can convert \(7 \frac{3}{10}\) into an improper fraction:

\[ 7 \frac{3}{10} = \frac{7 \times 10 + 3}{10} = \frac{70 + 3}{10} = \frac{73}{10} \]

Next, we need to add \(\frac{6}{10}\) to \(\frac{73}{10}\).

Since both fractions have the same denominator, we can simply add the numerators:

\[ \frac{73}{10} + \frac{6}{10} = \frac{73 + 6}{10} = \frac{79}{10} \]

Now, we convert \(\frac{79}{10}\) back to a mixed number:

\[ \frac{79}{10} = 7 \frac{9}{10} \]

Thus, the total amount of water Mackenzie poured into the pool is:

\[ \boxed{7 \frac{9}{10}} \text{ buckets} \]