1. The problem provides the sequence: 64, 49, 36, ?. We need to find the missing number. 2. Observe the given numbers are perfect squares: $$64 = 8^2$$ $$49 = 7^2$$ $$36 = 6^2$$ 3. The sequence appears to be decreasing perfect squares starting from 8 squared downwards by 1 each time. 4. Following this pattern, the next number is: $$5^2 = 25$$ 5. Therefore, the missing number in the sequence is **25**.