#### Answer

$11,557$

#### Work Step by Step

$321 + 9603 + 8 + 21 + 1604$
Start at the right of each number and add the ones digits
$1 + 3 + 8 + 1 + 4 = 17$ ones
Regroup the $17$ ones as $1$ ten and $7$ ones
Write the $7$ ones in the ones column.
Write the $1$ ten in the tens column
Add the tens column next including the regrouped $1$
$1 + 2 + 0 + 2 + 0 = 5$ tens
Write the $5$ tens in the tens column.
Add the hundreds column next
$3 + 6 + 6 = 15$ hundreds
Regroup the $15$ hundreds as $1$ thousand and $5$ hundreds
Write the $5$ hundreds in the hundreds column
Write the $1$ thousand in the thousands column.
Add the thousands column next including the regrouped $1$
$1 + 9 + 1 = 11$ thousands
Regroup the $11$ thousands as $1$ ten-thousand and $1$ thousand
Write the $1$ in the thousands column.
Write the $1$ in the ten-thousands column
Add the ten-thousands column next which is the regrouped $1$
Write the $1$ in the ten-thousands column.
$11557$
Separate each group of three digits with a comma.
The sum of the five numbers is $11,557$