Chapter 1 - Whole Numbers - 1.2 Adding Whole Numbers - 1.2 Exercises - Page 19: 55

$12,078$

$2109 + 63 + 16 + 3 + 9887$ Start at the right of each number and add the ones digits $9 + 3 + 6 + 3 + 7 = 28$ ones Regroup the $28$ ones as $2$ tens and $8$ ones Write the $8$ ones in the ones column. Write the $2$ tens in the tens column Add the tens column next including the regrouped $2$ $2 + 0 + 6 + 1 + 8 = 17$ tens Regroup the $17$ tens as $1$ hundred and $7$ tens Write the $7$ tens in the tens column. Write the $1$ hundred in the hundreds column Add the hundreds column next including the regrouped $1$ $1 + 1 + 8 = 10$ hundreds Regroup the $10$ hundreds as $1$ thousand and $0$ hundreds Write the $0$ hundreds in the hundreds column Write the $1$ thousand in the thousands column. Add the thousands column next including the regrouped $1$ $1 + 2 + 9 = 12$ thousands Regroup the $12$ thousands as $1$ ten-thousand and $2$ thousands Write the $2$ thousands in the thousands column. Write the $1$ ten-thousand in the ten-thousands column Add the ten-thousands column next which is the regrouped $1$ Write the $1$ in the ten-thousands column. $12078$ Separate each group of three digits with a comma. The sum of the five numbers is $12,078$