Find the sum.

$-104+53$

To add two numbers with similar signs, add their absolute values and keep the similar sign with the resulting number.

To add two numbers with opposite signs, subtract the absolute value of smaller number from absolute value of larger number and keep the sign of larger number with the resulting number.

If two positive numbers 2 and 3 are added, then the resulting sum will be $2+3=5$, which is positive as well.

And if two negative numbers $-2$ and $-3$ are added, then the resulting sum will be $\left(-2\right)+\left(-3\right)=-5$, which is negative as well.

Observe that the numbers – 104 and 53 have different signs, so the numbers will subtract and the resulting number will carry the sign of larger number, that is, negative.

The sum of the numbers can be computed as shown below,

$-104+53=-51$

Thus, the sum of the given numbers is $-51$.