You have already learned how to use column addition. Sometimes, though, you carry (regroup) numbers from one place value to the next.
Look at this addition problem:
29
+ 17
You know to add the numbers in the ones column first. Remember, the sum of 9 + 7 equals 16. But you can't write 16 in the ones place (ones column) of your answer.
29
+ 17
16
There are other digits you add in the tens place (tens column). We can't put the one there. We have to carry.
We will leave the 6 in the ones column of the sum. Then we will carry the one ten to the tens column. Place the one in small print above the digits in the tens column.
1
29
+ 17
6
Now add all the numbers in the tens column. What is the sum (answer) of 1 + 2 + 1? The answer is 4. Write 4 in the tens column.
29
+ 17
46
You've solved the problem! The sum of 29 + 17 equals 46.
Remember, if the answer in the ones column has two digits, carry the tens digit to the tens column.
Let's try one more.
26
+ 26
What's the sum of the ones column? Yes-6 + 6 equals 12. What do you do? You write the 2 in the ones column and carry the one to the tens column.
1
26
+ 26
2
Now, what is the sum of the tens column? Right-1 + 2 + 2 equals 5. Write the 5 in the tens column of the sum.
26
+ 26
52
You've solved the problem! The sum of 26 + 26 equals 52.
