To find the weight of each science textbook, you can divide the total weight of the textbooks by the number of textbooks.
The total weight of the 5 science textbooks is \( 6 + \frac{2}{3} \) pounds. First, let's convert the mixed number into an improper fraction:
\[ 6 + \frac{2}{3} = \frac{6 \times 3}{3} + \frac{2}{3} = \frac{18}{3} + \frac{2}{3} = \frac{20}{3} \text{ pounds} \]
Now, divide this total weight by 5 to find the weight of each textbook:
\[ \text{Weight of each book} = \frac{\frac{20}{3}}{5} = \frac{20}{3} \times \frac{1}{5} = \frac{20}{15} = \frac{4}{3} \text{ pounds} \]
Thus, each science textbook weighs \( \frac{4}{3} \) pounds, which is equivalent to \( 1 \frac{1}{3} \) pounds.