3-Digit Addition

There are four basic arithmetic operations in math: addition, subtraction, multiplication, and division. Addition is a mathematical operation where we add two or more numbers together to find the result. The result of adding numbers is known as the sum. The symbol used to represent addition is ‘+’. In our daily life, we use addition to calculate the values and measure quantities. For example, to calculate the daily income, scores on exams, or to calculate the score in games.

Two parts of addition are addends and the sum. The numbers that are added are the addends, and the result is the sum. To add numbers, we first arrange the numbers based on the place values, then add the digits from the ones place, then tens, and hundreds. In 3-digit addition, the numbers range from 100 to 999 and can be done with or without regrouping. Moreover, we have to follow some steps to perform this type of addition. They are: 

Step 1: According to the place values - ones, tens, and hundreds - arrange the numbers one below the other.

Step 2: Start adding from right to left, so we start from the one place, then the tens, then the hundreds.

Step 3: After finishing the addition, write the result as the sum. 

The 3-digit addition without regrouping is when the sum of the digits in each place value is less than or equal to 9. The numbers in the same place columns will be added, and then the result is written under the corresponding column. We can learn this using an example : 

Let us add 257 and 432. 

Step 1: First, add the numbers under the ones column. 
             7 + 2 = 9
            Write 9 in the ones column. 

Step 2: Add the numbers in the tens column. 
            5 + 3 = 8 
            Put 8 in the tens column. 

Step 3: Finally, add the numbers in the hundreds column. 
           2 + 4 = 6
           Write 6 in the hundreds' column.

Therefore, the sum of 257 and 432 is 689.

Addition with regrouping can be done if the sum of digits in any place column is greater than 9, we carry over the extra value to the next place column on the left. For instance, we can learn 3-digit addition with regrouping by adding 671 and 154. 

Step 1: To begin, add the numbers in the ones column.
            1 + 4 = 5
            Write 5 in the ones column. 

Step 2: Add the numbers in the tens column. 
        7 + 5 = 12
        Write 2 in the tens column and carry 1 to the hundreds' column. 

Step 3: Finally, add the numbers in the hundreds' column. This means 6 + 1 + 1 (carry over). 
           6 + 1 + 1 = 8
           Write 8 in the hundreds' column. 

Therefore, the sum of 671 and 154 is 825.

In our daily lives, we use the 3-digit addition method in various situations, from counting to planning events for a large group. Here are some real-world applications of this type of addition.

• While shopping, we need to calculate the total cost of multiple items to know the total expenditure. If the prices are larger than 100 and less than 999, we can use the 3-digit addition. For example, if we buy 3 pieces of furniture for $321, $542, and $873, then the total sum will be:
  $321 + $542 + $873 = $1736
  $1736 will be the total cost for the three pieces of furniture.

• When we go on a tour, we use 3-digit addition to calculate the distance we cover. For example, if we drive 130 km to Georgia, then 432 to Washington, the total distance we cover is:
  130 +432 = 562 km

• If we plan a function, we must calculate the number of guests who will attend the event. For instance, if we plan to invite 200 relatives, 100 friends, and 200 others, then the total number of guests will be:
  200 + 100 + 200 = 500 guests.

• When we invest in banks, we must calculate our savings to know the balance. For instance, if we invest $100 in January and $650 in April, then the total balance is:
  100 + 650 = $750