Add 13 and 21 Find the Sum of 895 and 152 Increase one gross by one score

"Add 13 and 21" means to find the sum of these two numbers.

$$13 + 21 = 34$$

The sum is $\boxed{\text{34}}$.

"Find the Sum of 895 and 152" means to add these two numbers together.

$$895 + 152 = 1047$$

The sum is $\boxed{\text{1047}}$.

"Increase one gross by one score" requires knowing the values of "gross" and "score".
One gross is equal to 144.
One score is equal to 20.
To increase one gross by one score, we add these values:

$$144 + 20 = 164$$

The result is $\boxed{\text{164}}$.